Babylon.js/src/babylon.scene.ts

module BABYLON {
    export interface IDisposable {
        dispose(): void;
    }

    class ClickInfo {
        private _singleClick = false;
        private _doubleClick = false;
        private _hasSwiped = false;
        private _ignore = false;

        public get singleClick(): boolean {
            return this._singleClick;
        }
        public get doubleClick(): boolean {
            return this._doubleClick;
        }
        public get hasSwiped(): boolean{
            return this._hasSwiped;
        }
        public get ignore(): boolean{
            return this._ignore;
        }

        public set singleClick(b: boolean) {
            this._singleClick = b;
        }
        public set doubleClick(b: boolean) {
            this._doubleClick = b;
        }
        public set hasSwiped(b: boolean) {
            this._hasSwiped = b;
        }
        public set ignore(b: boolean) {
            this._ignore = b;
        }
    }

    export class PointerEventTypes {
        static _POINTERDOWN = 0x01;
        static _POINTERUP = 0x02;
        static _POINTERMOVE = 0x04;
        static _POINTERWHEEL = 0x08;
        static _POINTERPICK = 0x10;
        static _POINTERTAP = 0x20;
        static _POINTERDOUBLETAP = 0x40;

        public static get POINTERDOWN(): number {
            return PointerEventTypes._POINTERDOWN;
        }

        public static get POINTERUP(): number {
            return PointerEventTypes._POINTERUP;
        }

        public static get POINTERMOVE(): number {
            return PointerEventTypes._POINTERMOVE;
        }

        public static get POINTERWHEEL(): number {
            return PointerEventTypes._POINTERWHEEL;
        }

        public static get POINTERPICK(): number {
            return PointerEventTypes._POINTERPICK;
        }
        
        public static get POINTERTAP(): number {
            return PointerEventTypes._POINTERTAP;
        }

        public static get POINTERDOUBLETAP(): number {
            return PointerEventTypes._POINTERDOUBLETAP;
        }
    }

    export class PointerInfoBase {
        constructor(public type: number, public event: PointerEvent | MouseWheelEvent) {
        }

    }

    /**
     * This class is used to store pointer related info for the onPrePointerObservable event.
     * Set the skipOnPointerObservable property to true if you want the engine to stop any process after this event is triggered, even not calling onPointerObservable
     */
    export class PointerInfoPre extends PointerInfoBase {
        constructor(type: number, event: PointerEvent | MouseWheelEvent, localX, localY) {
            super(type, event);
            this.skipOnPointerObservable = false;
            this.localPosition = new Vector2(localX, localY);
        }

        public localPosition: Vector2;
        public skipOnPointerObservable: boolean;
    }

    /**
     * This type contains all the data related to a pointer event in Babylon.js.
     * The event member is an instance of PointerEvent for all types except PointerWheel and is of type MouseWheelEvent when type equals PointerWheel. The different event types can be found in the PointerEventTypes class.
     */
    export class PointerInfo extends PointerInfoBase {
        constructor(type: number, event: PointerEvent | MouseWheelEvent, public pickInfo: PickingInfo) {
            super(type, event);
        }
    }

    /**
     * This class is used by the onRenderingGroupObservable
     */
    export class RenderingGroupInfo {
        /**
         * The Scene that being rendered
         */
        scene: Scene;

        /**
         * The camera currently used for the rendering pass
         */
        camera: Camera;

        /**
         * The ID of the renderingGroup being processed
         */
        renderingGroupId: number;

        /**
         * The rendering stage, can be either STAGE_PRECLEAR, STAGE_PREOPAQUE, STAGE_PRETRANSPARENT, STAGE_POSTTRANSPARENT
         */
        renderStage: number;

        /**
         * Stage corresponding to the very first hook in the renderingGroup phase: before the render buffer may be cleared
         * This stage will be fired no matter what
         */
        static STAGE_PRECLEAR = 1;

        /**
         * Called before opaque object are rendered.
         * This stage will be fired only if there's 3D Opaque content to render
         */
        static STAGE_PREOPAQUE = 2;

        /**
         * Called after the opaque objects are rendered and before the transparent ones
         * This stage will be fired only if there's 3D transparent content to render
         */
        static STAGE_PRETRANSPARENT = 3;

        /**
         * Called after the transparent object are rendered, last hook of the renderingGroup phase
         * This stage will be fired no matter what
         */
        static STAGE_POSTTRANSPARENT = 4;
    }

    /**
     * Represents a scene to be rendered by the engine.
     * @see http://doc.babylonjs.com/page.php?p=21911
     */
    export class Scene implements IAnimatable {
        // Statics
        private static _FOGMODE_NONE = 0;
        private static _FOGMODE_EXP = 1;
        private static _FOGMODE_EXP2 = 2;
        private static _FOGMODE_LINEAR = 3;

        public static MinDeltaTime = 1.0;
        public static MaxDeltaTime = 1000.0;

        public static get FOGMODE_NONE(): number {
            return Scene._FOGMODE_NONE;
        }

        public static get FOGMODE_EXP(): number {
            return Scene._FOGMODE_EXP;
        }

        public static get FOGMODE_EXP2(): number {
            return Scene._FOGMODE_EXP2;
        }

        public static get FOGMODE_LINEAR(): number {
            return Scene._FOGMODE_LINEAR;
        }

        // Members
        public autoClear = true;
        public autoClearDepthAndStencil = true;
        public clearColor: Color4 = new Color4(0.2, 0.2, 0.3, 1.0);
        public ambientColor = new Color3(0, 0, 0);

        public _environmentBRDFTexture: BaseTexture;

        protected _environmentTexture: BaseTexture;
        /**
         * Texture used in all pbr material as the reflection texture.
         * As in the majority of the scene they are the same (exception for multi room and so on),
         * this is easier to reference from here than from all the materials.
         */
        public get environmentTexture(): BaseTexture {
            return this._environmentTexture;
        }
        /**
         * Texture used in all pbr material as the reflection texture.
         * As in the majority of the scene they are the same (exception for multi room and so on),
         * this is easier to set here than in all the materials.
         */
        public set environmentTexture(value: BaseTexture) {
            this._environmentTexture = value;
            this.markAllMaterialsAsDirty(Material.TextureDirtyFlag);
        }

        protected _imageProcessingConfiguration: ImageProcessingConfiguration;
        /**
         * Default image processing configuration used either in the rendering
         * Forward main pass or through the imageProcessingPostProcess if present.
         * As in the majority of the scene they are the same (exception for multi camera),
         * this is easier to reference from here than from all the materials and post process.
         * 
         * No setter as we it is a shared configuration, you can set the values instead.
         */
        public get imageProcessingConfiguration(): ImageProcessingConfiguration {
            return this._imageProcessingConfiguration;
        }

        public forceWireframe = false;
        private _forcePointsCloud = false;
        public set forcePointsCloud(value : boolean) {
            if (this._forcePointsCloud === value) {
                return;
            }
            this._forcePointsCloud = value;
            this.markAllMaterialsAsDirty(Material.MiscDirtyFlag);
        }
        public get forcePointsCloud(): boolean {
            return this._forcePointsCloud;
        }   

        public forceShowBoundingBoxes = false;
        public clipPlane: Plane;
        public animationsEnabled = true;
        public constantlyUpdateMeshUnderPointer = false;

        public hoverCursor = "pointer";

        // Metadata
        public metadata: any = null;

        // Events

        /**
        * An event triggered when the scene is disposed.
        * @type {BABYLON.Observable}
        */
        public onDisposeObservable = new Observable<Scene>();

        private _onDisposeObserver: Observer<Scene>;
        public set onDispose(callback: () => void) {
            if (this._onDisposeObserver) {
                this.onDisposeObservable.remove(this._onDisposeObserver);
            }
            this._onDisposeObserver = this.onDisposeObservable.add(callback);
        }

        /**
        * An event triggered before rendering the scene
        * @type {BABYLON.Observable}
        */
        public onBeforeRenderObservable = new Observable<Scene>();

        private _onBeforeRenderObserver: Observer<Scene>;
        public set beforeRender(callback: () => void) {
            if (this._onBeforeRenderObserver) {
                this.onBeforeRenderObservable.remove(this._onBeforeRenderObserver);
            }
            this._onBeforeRenderObserver = this.onBeforeRenderObservable.add(callback);
        }

        /**
        * An event triggered after rendering the scene
        * @type {BABYLON.Observable}
        */
        public onAfterRenderObservable = new Observable<Scene>();

        private _onAfterRenderObserver: Observer<Scene>;
        public set afterRender(callback: () => void) {
            if (this._onAfterRenderObserver) {
                this.onAfterRenderObservable.remove(this._onAfterRenderObserver);
            }
            this._onAfterRenderObserver = this.onAfterRenderObservable.add(callback);
        }

        /**
        * An event triggered when the scene is ready
        * @type {BABYLON.Observable}
        */
        public onReadyObservable = new Observable<Scene>();

        /**
        * An event triggered before rendering a camera
        * @type {BABYLON.Observable}
        */
        public onBeforeCameraRenderObservable = new Observable<Camera>();

        private _onBeforeCameraRenderObserver: Observer<Camera>;
        public set beforeCameraRender(callback: () => void) {
            if (this._onBeforeCameraRenderObserver) {
                this.onBeforeCameraRenderObservable.remove(this._onBeforeCameraRenderObserver);
            }

            this._onBeforeCameraRenderObserver = this.onBeforeCameraRenderObservable.add(callback);
        }

        /**
        * An event triggered after rendering a camera
        * @type {BABYLON.Observable}
        */
        public onAfterCameraRenderObservable = new Observable<Camera>();

        private _onAfterCameraRenderObserver: Observer<Camera>;
        public set afterCameraRender(callback: () => void) {
            if (this._onAfterCameraRenderObserver) {
                this.onAfterCameraRenderObservable.remove(this._onAfterCameraRenderObserver);
            }
            this._onAfterCameraRenderObserver = this.onAfterCameraRenderObservable.add(callback);
        }

        /**
        * An event triggered when a camera is created
        * @type {BABYLON.Observable}
        */
        public onNewCameraAddedObservable = new Observable<Camera>();

        /**
        * An event triggered when a camera is removed
        * @type {BABYLON.Observable}
        */
        public onCameraRemovedObservable = new Observable<Camera>();

        /**
        * An event triggered when a light is created
        * @type {BABYLON.Observable}
        */
        public onNewLightAddedObservable = new Observable<Light>();

        /**
        * An event triggered when a light is removed
        * @type {BABYLON.Observable}
        */
        public onLightRemovedObservable = new Observable<Light>();

        /**
        * An event triggered when a geometry is created
        * @type {BABYLON.Observable}
        */
        public onNewGeometryAddedObservable = new Observable<Geometry>();

        /**
        * An event triggered when a geometry is removed
        * @type {BABYLON.Observable}
        */
        public onGeometryRemovedObservable = new Observable<Geometry>();

        /**
        * An event triggered when a mesh is created
        * @type {BABYLON.Observable}
        */
        public onNewMeshAddedObservable = new Observable<AbstractMesh>();

        /**
        * An event triggered when a mesh is removed
        * @type {BABYLON.Observable}
        */
        public onMeshRemovedObservable = new Observable<AbstractMesh>();

        /**
         * This Observable will be triggered for each stage of each renderingGroup of each rendered camera.
         * The RenderinGroupInfo class contains all the information about the context in which the observable is called
         * If you wish to register an Observer only for a given set of renderingGroup, use the mask with a combination of the renderingGroup index elevated to the power of two (1 for renderingGroup 0, 2 for renderingrOup1, 4 for 2 and 8 for 3)
         */
        public onRenderingGroupObservable = new Observable<RenderingGroupInfo>();

        // Animations
        public animations: Animation[] = [];

        // Pointers
        public pointerDownPredicate: (Mesh: AbstractMesh) => boolean;
        public pointerUpPredicate: (Mesh: AbstractMesh) => boolean;
        public pointerMovePredicate: (Mesh: AbstractMesh) => boolean;
        private _onPointerMove: (evt: PointerEvent) => void;
        private _onPointerDown: (evt: PointerEvent) => void;
        private _onPointerUp: (evt: PointerEvent) => void;

        public onPointerMove: (evt: PointerEvent, pickInfo: PickingInfo) => void;
        public onPointerDown: (evt: PointerEvent, pickInfo: PickingInfo) => void;
        public onPointerUp: (evt: PointerEvent, pickInfo: PickingInfo) => void;
        public onPointerPick: (evt: PointerEvent, pickInfo: PickingInfo) => void;

        /**
         * This observable event is triggered when any mouse event registered during Scene.attach() is called BEFORE the 3D engine to process anything (mesh/sprite picking for instance).
         * You have the possibility to skip the 3D Engine process and the call to onPointerObservable by setting PointerInfoBase.skipOnPointerObservable to true
         */
        public onPrePointerObservable = new Observable<PointerInfoPre>();

        /**
         * Observable event triggered each time an input event is received from the rendering canvas
         */
        public onPointerObservable = new Observable<PointerInfo>();

        public get unTranslatedPointer(): Vector2 {
            return new Vector2(this._unTranslatedPointerX, this._unTranslatedPointerY);
        }

        public static DragMovementThreshold = 10; // in pixels
        public static LongPressDelay = 500; // in milliseconds
        public static DoubleClickDelay = 300; // in milliseconds
        public static ExclusiveDoubleClickMode = false; // If you need to check double click without raising a single click at first click, enable this flag

        private _initClickEvent: (obs1: Observable<PointerInfoPre>, obs2: Observable<PointerInfo>, evt: PointerEvent, cb: (clickInfo: ClickInfo, pickResult: PointerInfo) => void) => void;
        private _initActionManager: (act: ActionManager, clickInfo: ClickInfo) => ActionManager;
        private _delayedSimpleClick: (btn: number, clickInfo: ClickInfo, cb: (clickInfo: ClickInfo, pickResult: PointerInfo) => void) => void;
        private _delayedSimpleClickTimeout;
        private _previousDelayedSimpleClickTimeout;
        private _meshPickProceed = false;

        private _previousButtonPressed;
        private _previousHasSwiped = false;
        private _currentPickResult = null;
        private _previousPickResult = null;
        private _isButtonPressed = false;
        private _doubleClickOccured = false;

        public cameraToUseForPointers: Camera = null; // Define this parameter if you are using multiple cameras and you want to specify which one should be used for pointer position
        private _pointerX: number;
        private _pointerY: number;
        private _unTranslatedPointerX: number;
        private _unTranslatedPointerY: number;
        private _startingPointerPosition = new Vector2(0, 0);
        private _previousStartingPointerPosition = new Vector2(0, 0);
        private _startingPointerTime = 0;
        private _previousStartingPointerTime = 0;
        
        // Mirror
        public _mirroredCameraPosition: Vector3;

        // Keyboard
        private _onKeyDown: (evt: Event) => void;
        private _onKeyUp: (evt: Event) => void;

        // Coordinate system
        /**
        * use right-handed coordinate system on this scene.
        * @type {boolean}
        */
        private _useRightHandedSystem = false;
        public set useRightHandedSystem(value: boolean) {
            if (this._useRightHandedSystem === value) {
                return;
            }
            this._useRightHandedSystem = value;
            this.markAllMaterialsAsDirty(Material.MiscDirtyFlag);
        }
        public get useRightHandedSystem(): boolean {
            return this._useRightHandedSystem;
        }

        // Fog
        /**
        * is fog enabled on this scene.
        * @type {boolean}
        */
        private _fogEnabled = true;
        public set fogEnabled(value : boolean) {
            if (this._fogEnabled === value) {
                return;
            }
            this._fogEnabled = value;
            this.markAllMaterialsAsDirty(Material.MiscDirtyFlag);
        }
        public get fogEnabled(): boolean {
            return this._fogEnabled;
        }   

        private _fogMode = Scene.FOGMODE_NONE;
        public set fogMode(value : number) {
            if (this._fogMode === value) {
                return;
            }
            this._fogMode = value;
            this.markAllMaterialsAsDirty(Material.MiscDirtyFlag);
        }
        public get fogMode(): number {
            return this._fogMode;
        }  

        public fogColor = new Color3(0.2, 0.2, 0.3);
        public fogDensity = 0.1;
        public fogStart = 0;
        public fogEnd = 1000.0;

        // Lights
        /**
        * is shadow enabled on this scene.
        * @type {boolean}
        */
        private _shadowsEnabled = true;
        public set shadowsEnabled(value : boolean) {
            if (this._shadowsEnabled === value) {
                return;
            }
            this._shadowsEnabled = value;
            this.markAllMaterialsAsDirty(Material.LightDirtyFlag);
        }
        public get shadowsEnabled(): boolean {
            return this._shadowsEnabled;
        }       

        /**
        * is light enabled on this scene.
        * @type {boolean}
        */
        private _lightsEnabled = true;
        public set lightsEnabled(value : boolean) {
            if (this._lightsEnabled === value) {
                return;
            }
            this._lightsEnabled = value;
            this.markAllMaterialsAsDirty(Material.LightDirtyFlag);
        }

        public get lightsEnabled(): boolean {
            return this._lightsEnabled;
        }

        /**
        * All of the lights added to this scene.
        * @see BABYLON.Light
        * @type {BABYLON.Light[]}
        */
        public lights = new Array<Light>();

        // Cameras
        /**
        * All of the cameras added to this scene.
        * @see BABYLON.Camera
        * @type {BABYLON.Camera[]}
        */
        public cameras = new Array<Camera>();
        public activeCameras = new Array<Camera>();
        public activeCamera: Camera;

        // Meshes
        /**
        * All of the (abstract) meshes added to this scene.
        * @see BABYLON.AbstractMesh
        * @type {BABYLON.AbstractMesh[]}
        */
        public meshes = new Array<AbstractMesh>();

        // Geometries
        private _geometries = new Array<Geometry>();

        public materials = new Array<Material>();
        public multiMaterials = new Array<MultiMaterial>();
        private _defaultMaterial: Material;

        public get defaultMaterial(): Material {
            if (!this._defaultMaterial) {
                this._defaultMaterial = new StandardMaterial("default material", this);
            }

            return this._defaultMaterial;
        }

        public set defaultMaterial(value: Material) {
            this._defaultMaterial = value;
        }

        // Textures
        private _texturesEnabled = true;
        public set texturesEnabled(value : boolean) {
            if (this._texturesEnabled === value) {
                return;
            }
            this._texturesEnabled = value;
            this.markAllMaterialsAsDirty(Material.TextureDirtyFlag);
        }

        public get texturesEnabled(): boolean {
            return this._texturesEnabled;
        }     

        public textures = new Array<BaseTexture>();

        // Particles
        public particlesEnabled = true;
        public particleSystems = new Array<ParticleSystem>();

        // Sprites
        public spritesEnabled = true;
        public spriteManagers = new Array<SpriteManager>();

        // Layers
        public layers = new Array<Layer>();
        public highlightLayers = new Array<HighlightLayer>();

        // Skeletons
        private _skeletonsEnabled = true;
        public set skeletonsEnabled(value : boolean) {
            if (this._skeletonsEnabled === value) {
                return;
            }
            this._skeletonsEnabled = value;
            this.markAllMaterialsAsDirty(Material.AttributesDirtyFlag);
        }

        public get skeletonsEnabled(): boolean {
            return this._skeletonsEnabled;
        }       

        public skeletons = new Array<Skeleton>();

        // Morph targets
        public morphTargetManagers = new Array<MorphTargetManager>();

        // Lens flares
        public lensFlaresEnabled = true;
        public lensFlareSystems = new Array<LensFlareSystem>();

        // Collisions
        public collisionsEnabled = true;
        private _workerCollisions;
        public collisionCoordinator: ICollisionCoordinator;
        public gravity = new Vector3(0, -9.807, 0);

        // Postprocesses
        public postProcessesEnabled = true;
        public postProcessManager: PostProcessManager;
        private _postProcessRenderPipelineManager: PostProcessRenderPipelineManager
        public get postProcessRenderPipelineManager(): PostProcessRenderPipelineManager {
            if (!this._postProcessRenderPipelineManager) {
                this._postProcessRenderPipelineManager = new PostProcessRenderPipelineManager();
            }

            return this._postProcessRenderPipelineManager;
        }

        // Customs render targets
        public renderTargetsEnabled = true;
        public dumpNextRenderTargets = false;
        public customRenderTargets = new Array<RenderTargetTexture>();

        // Delay loading
        public useDelayedTextureLoading: boolean;

        // Imported meshes
        public importedMeshesFiles = new Array<String>();

        // Probes
        public probesEnabled = true;
        public reflectionProbes = new Array<ReflectionProbe>();

        // Database
        public database; //ANY

        /**
         * This scene's action manager
         * @type {BABYLON.ActionManager}
        */
        public actionManager: ActionManager;

        public _actionManagers = new Array<ActionManager>();
        private _meshesForIntersections = new SmartArray<AbstractMesh>(256);

        // Procedural textures
        public proceduralTexturesEnabled = true;
        public _proceduralTextures = new Array<ProceduralTexture>();

        // Sound Tracks
        public mainSoundTrack: SoundTrack;
        public soundTracks = new Array<SoundTrack>();
        private _audioEnabled = true;
        private _headphone = false;

        //Simplification Queue
        public simplificationQueue: SimplificationQueue;

        // Private
        private _engine: Engine;

        // Performance counters
        private _totalMeshesCounter = new PerfCounter();
        private _totalLightsCounter = new PerfCounter();
        private _totalMaterialsCounter = new PerfCounter();
        private _totalTexturesCounter = new PerfCounter();
        private _totalVertices = new PerfCounter();
        public _activeIndices = new PerfCounter();
        public _activeParticles = new PerfCounter();
        private _lastFrameDuration = new PerfCounter();
        private _evaluateActiveMeshesDuration = new PerfCounter();
        private _renderTargetsDuration = new PerfCounter();
        public _particlesDuration = new PerfCounter();
        private _renderDuration = new PerfCounter();
        public _spritesDuration = new PerfCounter();
        public _activeBones = new PerfCounter();

        private _animationRatio: number;

        private _animationTimeLast: number;
        private _animationTime: number = 0;
        public animationTimeScale: number = 1;

        public _cachedMaterial: Material;
        public _cachedEffect: Effect;
        public _cachedVisibility: number;

        private _renderId = 0;
        private _executeWhenReadyTimeoutId = -1;
        private _intermediateRendering = false;

        private _viewUpdateFlag = -1;
        private _projectionUpdateFlag = -1;

        public _toBeDisposed = new SmartArray<IDisposable>(256);
        private _pendingData = [];//ANY

        private _activeMeshes = new SmartArray<Mesh>(256);
        private _processedMaterials = new SmartArray<Material>(256);
        private _renderTargets = new SmartArray<RenderTargetTexture>(256);
        public _activeParticleSystems = new SmartArray<ParticleSystem>(256);
        private _activeSkeletons = new SmartArray<Skeleton>(32);
        private _softwareSkinnedMeshes = new SmartArray<Mesh>(32);

        private _renderingManager: RenderingManager;
        private _physicsEngine: PhysicsEngine;

        public _activeAnimatables = new Array<Animatable>();

        private _transformMatrix = Matrix.Zero();
        private _sceneUbo: UniformBuffer;

        private _pickWithRayInverseMatrix: Matrix;
        
        private _boundingBoxRenderer: BoundingBoxRenderer;
        private _outlineRenderer: OutlineRenderer;

        private _viewMatrix: Matrix;
        private _projectionMatrix: Matrix;
        
        private _frustumPlanes: Plane[];
        public get frustumPlanes(): Plane[] {
            return this._frustumPlanes;
        }

        public requireLightSorting = false;

        private _selectionOctree: Octree<AbstractMesh>;

        private _pointerOverMesh: AbstractMesh;
        private _pointerOverSprite: Sprite;

        private _debugLayer: DebugLayer;

        private _depthRenderer: DepthRenderer;
        private _geometryBufferRenderer: GeometryBufferRenderer;

        private _uniqueIdCounter = 0;

        private _pickedDownMesh: AbstractMesh;
        private _pickedUpMesh: AbstractMesh;
        private _pickedDownSprite: Sprite;
        private _externalData: StringDictionary<Object>;
        private _uid: string;

        /**
         * @constructor
         * @param {BABYLON.Engine} engine - the engine to be used to render this scene.
         */
        constructor(engine: Engine) {
            this._engine = engine || Engine.LastCreatedEngine;

            this._engine.scenes.push(this);
            this._uid = null;

            this._renderingManager = new RenderingManager(this);

            this.postProcessManager = new PostProcessManager(this);

            if (OutlineRenderer) {
                this._outlineRenderer = new OutlineRenderer(this);
            }

            this.attachControl();

            if (SoundTrack) {
                this.mainSoundTrack = new SoundTrack(this, { mainTrack: true });
            }

            //simplification queue
            if (SimplificationQueue) {
                this.simplificationQueue = new SimplificationQueue();
            }

            //collision coordinator initialization. For now legacy per default.
            this.workerCollisions = false;//(!!Worker && (!!BABYLON.CollisionWorker || BABYLON.WorkerIncluded));

            // Uniform Buffer
            this._createUbo();

            // Default Image processing definition.
            this._imageProcessingConfiguration = new ImageProcessingConfiguration();
        }

        // Properties
        public get debugLayer(): DebugLayer {
            if (!this._debugLayer) {
                this._debugLayer = new DebugLayer(this);
            }
            return this._debugLayer;
        }

        public set workerCollisions(enabled: boolean) {
            if (!BABYLON.CollisionCoordinatorLegacy) {
                return;
            }

            enabled = (enabled && !!Worker);

            this._workerCollisions = enabled;
            if (this.collisionCoordinator) {
                this.collisionCoordinator.destroy();
            }

            this.collisionCoordinator = enabled ? new CollisionCoordinatorWorker() : new CollisionCoordinatorLegacy();

            this.collisionCoordinator.init(this);
        }

        public get workerCollisions(): boolean {
            return this._workerCollisions;
        }

        public get selectionOctree(): Octree<AbstractMesh> {
            return this._selectionOctree;
        }

        /**
         * The mesh that is currently under the pointer.
         * @return {BABYLON.AbstractMesh} mesh under the pointer/mouse cursor or null if none.
         */
        public get meshUnderPointer(): AbstractMesh {
            return this._pointerOverMesh;
        }

        /**
         * Current on-screen X position of the pointer
         * @return {number} X position of the pointer
         */
        public get pointerX(): number {
            return this._pointerX;
        }

        /**
         * Current on-screen Y position of the pointer
         * @return {number} Y position of the pointer
         */
        public get pointerY(): number {
            return this._pointerY;
        }

        public getCachedMaterial(): Material {
            return this._cachedMaterial;
        }

        public getCachedEffect(): Effect {
            return this._cachedEffect;
        }

        public getCachedVisibility(): number {
            return this._cachedVisibility;
        }

        public isCachedMaterialValid(material: Material, effect: Effect, visibility: number = 0) {
            return this._cachedEffect !== effect || this._cachedMaterial !== material || this._cachedVisibility !== visibility;
        }

        public getBoundingBoxRenderer(): BoundingBoxRenderer {
            if (!this._boundingBoxRenderer) {
                this._boundingBoxRenderer = new BoundingBoxRenderer(this);
            }

            return this._boundingBoxRenderer;
        }

        public getOutlineRenderer(): OutlineRenderer {
            return this._outlineRenderer;
        }

        public getEngine(): Engine {
            return this._engine;
        }

        public getTotalVertices(): number {
            return this._totalVertices.current;
        }

        public get totalVerticesPerfCounter(): PerfCounter {
            return this._totalVertices;
        }

        public getActiveIndices(): number {
            return this._activeIndices.current;
        }

        public get totalActiveIndicesPerfCounter(): PerfCounter {
            return this._activeIndices;
        }

        public getActiveParticles(): number {
            return this._activeParticles.current;
        }

        public get activeParticlesPerfCounter(): PerfCounter {
            return this._activeParticles;
        }

        public getActiveBones(): number {
            return this._activeBones.current;
        }

        public get activeBonesPerfCounter(): PerfCounter {
            return this._activeBones;
        }

        // Stats
        public getLastFrameDuration(): number {
            return this._lastFrameDuration.current;
        }

        public get lastFramePerfCounter(): PerfCounter {
            return this._lastFrameDuration;
        }

        public getEvaluateActiveMeshesDuration(): number {
            return this._evaluateActiveMeshesDuration.current;
        }

        public get evaluateActiveMeshesDurationPerfCounter(): PerfCounter {
            return this._evaluateActiveMeshesDuration;
        }

        public getActiveMeshes(): SmartArray<Mesh> {
            return this._activeMeshes;
        }

        public getRenderTargetsDuration(): number {
            return this._renderTargetsDuration.current;
        }

        public getRenderDuration(): number {
            return this._renderDuration.current;
        }

        public get renderDurationPerfCounter(): PerfCounter {
            return this._renderDuration;
        }

        public getParticlesDuration(): number {
            return this._particlesDuration.current;
        }

        public get particlesDurationPerfCounter(): PerfCounter {
            return this._particlesDuration;
        }

        public getSpritesDuration(): number {
            return this._spritesDuration.current;
        }

        public get spriteDuractionPerfCounter(): PerfCounter {
            return this._spritesDuration;
        }

        public getAnimationRatio(): number {
            return this._animationRatio;
        }

        public getRenderId(): number {
            return this._renderId;
        }

        public incrementRenderId(): void {
            this._renderId++;
        }

        private _updatePointerPosition(evt: PointerEvent): void {
            var canvasRect = this._engine.getRenderingCanvasClientRect();

            this._pointerX = evt.clientX - canvasRect.left;
            this._pointerY = evt.clientY - canvasRect.top;

            this._unTranslatedPointerX = this._pointerX;
            this._unTranslatedPointerY = this._pointerY;

            if (this.cameraToUseForPointers) {
                this._pointerX = this._pointerX - this.cameraToUseForPointers.viewport.x * this._engine.getRenderWidth();
                this._pointerY = this._pointerY - this.cameraToUseForPointers.viewport.y * this._engine.getRenderHeight();
            }
        }

        private _createUbo(): void {
            this._sceneUbo = new UniformBuffer(this._engine, null, true);
            this._sceneUbo.addUniform("viewProjection", 16);
            this._sceneUbo.addUniform("view", 16);
        }

        // Pointers handling

        /**
        * Attach events to the canvas (To handle actionManagers triggers and raise onPointerMove, onPointerDown and onPointerUp
        * @param attachUp defines if you want to attach events to pointerup
        * @param attachDown defines if you want to attach events to pointerdown
        * @param attachMove defines if you want to attach events to pointermove
        */
        public attachControl(attachUp = true, attachDown = true, attachMove = true) {
            this._initActionManager = (act: ActionManager, clickInfo: ClickInfo): ActionManager => {
                if (!this._meshPickProceed) {
                    let pickResult = this.pick(this._unTranslatedPointerX, this._unTranslatedPointerY, this.pointerDownPredicate, false, this.cameraToUseForPointers);
                    this._currentPickResult = pickResult;
                    if (pickResult) {
                        act = (pickResult.hit && pickResult.pickedMesh) ? pickResult.pickedMesh.actionManager : null;
                    }
                    this._meshPickProceed = true;
                }
                return act;
            };

            this._delayedSimpleClick = (btn: number, clickInfo: ClickInfo, cb: (clickInfo: ClickInfo, pickResult: PointerInfo) => void) => {
                // double click delay is over and that no double click has been raised since, or the 2 consecutive keys pressed are different
                if ((new Date().getTime() - this._previousStartingPointerTime > Scene.DoubleClickDelay && !this._doubleClickOccured) ||
                btn !== this._previousButtonPressed ) {
                    this._doubleClickOccured = false;
                    clickInfo.singleClick = true;
                    clickInfo.ignore = false;
                    cb(clickInfo, this._currentPickResult);
                }
            }

            this._initClickEvent = (obs1: Observable<PointerInfoPre>, obs2: Observable<PointerInfo>, evt: PointerEvent, cb: (clickInfo: ClickInfo, pickResult: PointerInfo) => void): void => {
                    let clickInfo = new ClickInfo();
                    this._currentPickResult = null;
                    let act;

                    let checkPicking = obs1.hasSpecificMask(PointerEventTypes.POINTERPICK) || obs2.hasSpecificMask(PointerEventTypes.POINTERPICK)
                                    || obs1.hasSpecificMask(PointerEventTypes.POINTERTAP) || obs2.hasSpecificMask(PointerEventTypes.POINTERTAP)
                                    || obs1.hasSpecificMask(PointerEventTypes.POINTERDOUBLETAP) || obs2.hasSpecificMask(PointerEventTypes.POINTERDOUBLETAP);
                    if (!checkPicking && BABYLON.ActionManager && ActionManager.HasPickTriggers) {
                        act = this._initActionManager(act, clickInfo);
                        if (act)
                            checkPicking = act.hasPickTriggers;
                    }
                    if (checkPicking) {
                        let btn = evt.button;
                        clickInfo.hasSwiped = Math.abs(this._startingPointerPosition.x - this._pointerX) > Scene.DragMovementThreshold ||
                                              Math.abs(this._startingPointerPosition.y - this._pointerY) > Scene.DragMovementThreshold;

                        if (!clickInfo.hasSwiped) {
                            let checkSingleClickImmediately = !Scene.ExclusiveDoubleClickMode;

                            if (!checkSingleClickImmediately) {
                                checkSingleClickImmediately = !obs1.hasSpecificMask(PointerEventTypes.POINTERDOUBLETAP) &&
                                                              !obs2.hasSpecificMask(PointerEventTypes.POINTERDOUBLETAP);

                                if (checkSingleClickImmediately && !ActionManager.HasSpecificTrigger(ActionManager.OnDoublePickTrigger)) {
                                    act = this._initActionManager(act, clickInfo);
                                    if (act)
                                        checkSingleClickImmediately = !act.hasSpecificTrigger(ActionManager.OnDoublePickTrigger);
                                }
                            }

                            if (checkSingleClickImmediately) {
                                // single click detected if double click delay is over or two different successive keys pressed without exclusive double click or no double click required
                                if (new Date().getTime() - this._previousStartingPointerTime > Scene.DoubleClickDelay ||
                                    btn !== this._previousButtonPressed ) {
                                        clickInfo.singleClick = true;
                                        cb(clickInfo, this._currentPickResult);
                                }
                            }
                            // at least one double click is required to be check and exclusive double click is enabled
                            else {
                                // wait that no double click has been raised during the double click delay
                                this._previousDelayedSimpleClickTimeout = this._delayedSimpleClickTimeout;
                                this._delayedSimpleClickTimeout = window.setTimeout(this._delayedSimpleClick.bind(this, btn, clickInfo, cb), Scene.DoubleClickDelay);
                            }

                            let checkDoubleClick = obs1.hasSpecificMask(PointerEventTypes.POINTERDOUBLETAP) ||
                                                   obs2.hasSpecificMask(PointerEventTypes.POINTERDOUBLETAP);
                            if (!checkDoubleClick && ActionManager.HasSpecificTrigger(ActionManager.OnDoublePickTrigger)){
                                act = this._initActionManager(act, clickInfo);
                                if (act)
                                    checkDoubleClick = act.hasSpecificTrigger(ActionManager.OnDoublePickTrigger);
                            }
                            if (checkDoubleClick) {
                                // two successive keys pressed are equal, double click delay is not over and double click has not just occurred
                                if (btn === this._previousButtonPressed &&
                                    new Date().getTime() - this._previousStartingPointerTime < Scene.DoubleClickDelay &&
                                    !this._doubleClickOccured
                                ) {
                                    // pointer has not moved for 2 clicks, it's a double click
                                    if (!clickInfo.hasSwiped &&
                                        Math.abs(this._previousStartingPointerPosition.x - this._startingPointerPosition.x) < Scene.DragMovementThreshold &&
                                        Math.abs(this._previousStartingPointerPosition.y - this._startingPointerPosition.y) < Scene.DragMovementThreshold) {
                                        this._previousStartingPointerTime = 0;
                                        this._doubleClickOccured = true;
                                        clickInfo.doubleClick = true;
                                        clickInfo.ignore = false;
                                        if (Scene.ExclusiveDoubleClickMode && this._previousDelayedSimpleClickTimeout && this._previousDelayedSimpleClickTimeout.clearTimeout)
                                            this._previousDelayedSimpleClickTimeout.clearTimeout();
                                        this._previousDelayedSimpleClickTimeout = this._delayedSimpleClickTimeout;
                                        cb(clickInfo, this._currentPickResult);
                                    }
                                    // if the two successive clicks are too far, it's just two simple clicks
                                    else {
                                        this._doubleClickOccured = false;
                                        this._previousStartingPointerTime = this._startingPointerTime;
                                        this._previousStartingPointerPosition.x = this._startingPointerPosition.x;
                                        this._previousStartingPointerPosition.y = this._startingPointerPosition.y;
                                        this._previousButtonPressed = btn;
                                        this._previousHasSwiped = clickInfo.hasSwiped;
                                        if (Scene.ExclusiveDoubleClickMode){
                                            if (this._previousDelayedSimpleClickTimeout && this._previousDelayedSimpleClickTimeout.clearTimeout) {
                                                this._previousDelayedSimpleClickTimeout.clearTimeout();
                                            }
                                            this._previousDelayedSimpleClickTimeout = this._delayedSimpleClickTimeout;
                                            cb(clickInfo, this._previousPickResult);
                                        }
                                        else {
                                            cb(clickInfo, this._currentPickResult);
                                        }
                                    }
                                }
                                // just the first click of the double has been raised
                                else {
                                    this._doubleClickOccured = false;
                                    this._previousStartingPointerTime = this._startingPointerTime;
                                    this._previousStartingPointerPosition.x = this._startingPointerPosition.x;
                                    this._previousStartingPointerPosition.y = this._startingPointerPosition.y;
                                    this._previousButtonPressed = btn;
                                    this._previousHasSwiped = clickInfo.hasSwiped;
                                }
                            }
                        }
                    }
                    clickInfo.ignore = true;
                    cb(clickInfo, this._currentPickResult);
            };

            var spritePredicate = (sprite: Sprite): boolean => {
                return sprite.isPickable && sprite.actionManager && sprite.actionManager.hasPointerTriggers;
            };

            this._onPointerMove = (evt: PointerEvent) => {

                this._updatePointerPosition(evt);

                // PreObservable support
                if (this.onPrePointerObservable.hasObservers()) {
                    let type = evt.type === "mousewheel" || evt.type === "DOMMouseScroll" ? PointerEventTypes.POINTERWHEEL : PointerEventTypes.POINTERMOVE;
                    let pi = new PointerInfoPre(type, evt, this._unTranslatedPointerX, this._unTranslatedPointerY);
                    this.onPrePointerObservable.notifyObservers(pi, type);
                    if (pi.skipOnPointerObservable) {
                        return;
                    }
                }

                if (!this.cameraToUseForPointers && !this.activeCamera) {
                    return;
                }

                var canvas = this._engine.getRenderingCanvas();

                if (!this.pointerMovePredicate) {
                    this.pointerMovePredicate = (mesh: AbstractMesh): boolean => mesh.isPickable && mesh.isVisible && mesh.isReady() && mesh.isEnabled() && (this.constantlyUpdateMeshUnderPointer || (mesh.actionManager !== null && mesh.actionManager !== undefined));
                }

                // Meshes
                var pickResult = this.pick(this._unTranslatedPointerX, this._unTranslatedPointerY, this.pointerMovePredicate, false, this.cameraToUseForPointers);

                if (pickResult && pickResult.hit && pickResult.pickedMesh) {
                    this.setPointerOverSprite(null);

                    this.setPointerOverMesh(pickResult.pickedMesh);

                    if (this._pointerOverMesh.actionManager && this._pointerOverMesh.actionManager.hasPointerTriggers) {
                        if (this._pointerOverMesh.actionManager.hoverCursor) {
                            canvas.style.cursor = this._pointerOverMesh.actionManager.hoverCursor;
                        } else {
                            canvas.style.cursor = this.hoverCursor;
                        }
                    } else {
                        canvas.style.cursor = "";
                    }
                } else {
                    this.setPointerOverMesh(null);
                    // Sprites
                    pickResult = this.pickSprite(this._unTranslatedPointerX, this._unTranslatedPointerY, spritePredicate, false, this.cameraToUseForPointers);

                    if (pickResult && pickResult.hit && pickResult.pickedSprite) {
                        this.setPointerOverSprite(pickResult.pickedSprite);
                        if (this._pointerOverSprite.actionManager && this._pointerOverSprite.actionManager.hoverCursor) {
                            canvas.style.cursor = this._pointerOverSprite.actionManager.hoverCursor;
                        } else {
                            canvas.style.cursor = this.hoverCursor;
                        }
                    } else {
                        this.setPointerOverSprite(null);
                        // Restore pointer
                        canvas.style.cursor = "";
                    }
                }

                if (this.onPointerMove) {
                    this.onPointerMove(evt, pickResult);
                }

                if (this.onPointerObservable.hasObservers()) {
                    let type = evt.type === "mousewheel" || evt.type === "DOMMouseScroll" ? PointerEventTypes.POINTERWHEEL : PointerEventTypes.POINTERMOVE;
                    let pi = new PointerInfo(type, evt, pickResult);
                    this.onPointerObservable.notifyObservers(pi, type);
                }
            };

            this._onPointerDown = (evt: PointerEvent) => {
                this._isButtonPressed = true;
                this._pickedDownMesh = null;
                this._meshPickProceed = false;

                this._updatePointerPosition(evt);

                // PreObservable support
                if (this.onPrePointerObservable.hasObservers()) {
                    let type = PointerEventTypes.POINTERDOWN;
                    let pi = new PointerInfoPre(type, evt, this._unTranslatedPointerX, this._unTranslatedPointerY);
                    this.onPrePointerObservable.notifyObservers(pi, type);
                    if (pi.skipOnPointerObservable) {
                        return;
                    }
                }

                if (!this.cameraToUseForPointers && !this.activeCamera) {
                    return;
                }

                this._startingPointerPosition.x = this._pointerX;
                this._startingPointerPosition.y = this._pointerY;
                this._startingPointerTime = new Date().getTime();

                if (!this.pointerDownPredicate) {
                    this.pointerDownPredicate = (mesh: AbstractMesh): boolean => {
                        return mesh.isPickable && mesh.isVisible && mesh.isReady() && mesh.isEnabled();
                    };
                }

                // Meshes
                this._pickedDownMesh = null;
                var pickResult = this.pick(this._unTranslatedPointerX, this._unTranslatedPointerY, this.pointerDownPredicate, false, this.cameraToUseForPointers);

                if (pickResult && pickResult.hit && pickResult.pickedMesh) {
                    this._pickedDownMesh = pickResult.pickedMesh;
                    var actionManager = pickResult.pickedMesh.actionManager;
                    if (actionManager) {
                        if (actionManager.hasPickTriggers) {
                            actionManager.processTrigger(ActionManager.OnPickDownTrigger, ActionEvent.CreateNew(pickResult.pickedMesh, evt));
                            switch (evt.button) {
                                case 0:
                                    actionManager.processTrigger(ActionManager.OnLeftPickTrigger, ActionEvent.CreateNew(pickResult.pickedMesh, evt));
                                    break;
                                case 1:
                                    actionManager.processTrigger(ActionManager.OnCenterPickTrigger, ActionEvent.CreateNew(pickResult.pickedMesh, evt));
                                    break;
                                case 2:
                                    actionManager.processTrigger(ActionManager.OnRightPickTrigger, ActionEvent.CreateNew(pickResult.pickedMesh, evt));
                                    break;
                            }
                        }

                        if (actionManager.hasSpecificTrigger(ActionManager.OnLongPressTrigger)) {
                            window.setTimeout((function () {
                                var pickResult = this.pick(this._unTranslatedPointerX, this._unTranslatedPointerY,
                                    (mesh: AbstractMesh): boolean => mesh.isPickable && mesh.isVisible && mesh.isReady() && mesh.actionManager && mesh.actionManager.hasSpecificTrigger(ActionManager.OnLongPressTrigger) && mesh == this._pickedDownMesh,
                                    false, this.cameraToUseForPointers);

                                if (pickResult && pickResult.hit && pickResult.pickedMesh) {
                                    if (this._isButtonPressed &&
                                        ((new Date().getTime() - this._startingPointerTime) > Scene.LongPressDelay) &&
                                        (Math.abs(this._startingPointerPosition.x - this._pointerX) < Scene.DragMovementThreshold &&
                                         Math.abs(this._startingPointerPosition.y - this._pointerY) < Scene.DragMovementThreshold)) {
                                            this._startingPointerTime = 0;
                                            actionManager.processTrigger(ActionManager.OnLongPressTrigger, ActionEvent.CreateNew(pickResult.pickedMesh, evt));
                                    }
                                }
                            }).bind(this), Scene.LongPressDelay);
                        }
                    }
                }

                if (this.onPointerDown) {
                    this.onPointerDown(evt, pickResult);
                }

                if (this.onPointerObservable.hasObservers()) {
                    let type = PointerEventTypes.POINTERDOWN;
                    let pi = new PointerInfo(type, evt, pickResult);
                    this.onPointerObservable.notifyObservers(pi, type);
                }

                // Sprites
                this._pickedDownSprite = null;
                if (this.spriteManagers.length > 0) {
                    pickResult = this.pickSprite(this._unTranslatedPointerX, this._unTranslatedPointerY, spritePredicate, false, this.cameraToUseForPointers);

                    if (pickResult && pickResult.hit && pickResult.pickedSprite) {
                        if (pickResult.pickedSprite.actionManager) {
                            this._pickedDownSprite = pickResult.pickedSprite;
                            switch (evt.button) {
                                case 0:
                                    pickResult.pickedSprite.actionManager.processTrigger(ActionManager.OnLeftPickTrigger, ActionEvent.CreateNewFromSprite(pickResult.pickedSprite, this, evt));
                                    break;
                                case 1:
                                    pickResult.pickedSprite.actionManager.processTrigger(ActionManager.OnCenterPickTrigger, ActionEvent.CreateNewFromSprite(pickResult.pickedSprite, this, evt));
                                    break;
                                case 2:
                                    pickResult.pickedSprite.actionManager.processTrigger(ActionManager.OnRightPickTrigger, ActionEvent.CreateNewFromSprite(pickResult.pickedSprite, this, evt));
                                    break;
                            }
                            if (pickResult.pickedSprite.actionManager) {
                                pickResult.pickedSprite.actionManager.processTrigger(ActionManager.OnPickDownTrigger, ActionEvent.CreateNewFromSprite(pickResult.pickedSprite, this, evt));
                            }
                        }
                    }
                }
            };

            this._onPointerUp = (evt: PointerEvent) => {
                this._isButtonPressed = false;
                this._pickedUpMesh = null;
                this._meshPickProceed = false;

                this._updatePointerPosition(evt);

                this._initClickEvent(this.onPrePointerObservable, this.onPointerObservable,  evt, (function(clickInfo, pickResult){
                    // PreObservable support
                    if (this.onPrePointerObservable.hasObservers()) {
                        if (!clickInfo.ignore) {
                            if (!clickInfo.hasSwiped) {
                                if (clickInfo.singleClick && this.onPrePointerObservable.hasSpecificMask(PointerEventTypes.POINTERTAP)) {
                                    let type = PointerEventTypes.POINTERTAP;
                                    let pi = new PointerInfoPre(type, evt, this._unTranslatedPointerX, this._unTranslatedPointerY);
                                    this.onPrePointerObservable.notifyObservers(pi, type);
                                    if (pi.skipOnPointerObservable) {
                                        return;
                                    }
                                }
                                if (clickInfo.doubleClick && this.onPrePointerObservable.hasSpecificMask(PointerEventTypes.POINTERDOUBLETAP)) {
                                    let type = PointerEventTypes.POINTERDOUBLETAP;
                                    let pi = new PointerInfoPre(type, evt, this._unTranslatedPointerX, this._unTranslatedPointerY);
                                    this.onPrePointerObservable.notifyObservers(pi, type);
                                    if (pi.skipOnPointerObservable) {
                                        return;
                                    }
                                }
                            }
                        }
                        else {
                            let type = PointerEventTypes.POINTERUP;
                            let pi = new PointerInfoPre(type, evt, this._unTranslatedPointerX, this._unTranslatedPointerY);
                            this.onPrePointerObservable.notifyObservers(pi, type);
                            if (pi.skipOnPointerObservable) {
                                return;
                            }
                        }
                    }

                    if (!this.cameraToUseForPointers && !this.activeCamera) {
                        return;
                    }

                    if (!this.pointerUpPredicate) {
                        this.pointerUpPredicate = (mesh: AbstractMesh): boolean => {
                            return mesh.isPickable && mesh.isVisible && mesh.isReady() && mesh.isEnabled();
                        };
                    }

                    // Meshes
                    if (!this._meshPickProceed && (BABYLON.ActionManager && ActionManager.HasTriggers || this.onPointerObservable.hasObservers())) {
                        this._initActionManager(null, clickInfo);
                    }
                    if (!pickResult) {
                        pickResult = this._currentPickResult;
                    }

                    if (pickResult && pickResult && pickResult.pickedMesh) {
                        this._pickedUpMesh = pickResult.pickedMesh;
                        if (this._pickedDownMesh === this._pickedUpMesh) {
                            if (this.onPointerPick) {
                                this.onPointerPick(evt, pickResult);
                            }
                            if (clickInfo.singleClick && !clickInfo.ignore && this.onPointerObservable.hasObservers()) {
                                let type = PointerEventTypes.POINTERPICK;
                                let pi = new PointerInfo(type, evt, pickResult);
                                this.onPointerObservable.notifyObservers(pi, type);
                            }
                        }
                        if (pickResult.pickedMesh.actionManager) {
                            if (clickInfo.ignore) {
                                pickResult.pickedMesh.actionManager.processTrigger(ActionManager.OnPickUpTrigger, ActionEvent.CreateNew(pickResult.pickedMesh, evt));
                            }
                            if (!clickInfo.hasSwiped && !clickInfo.ignore && clickInfo.singleClick) {
                                pickResult.pickedMesh.actionManager.processTrigger(ActionManager.OnPickTrigger, ActionEvent.CreateNew(pickResult.pickedMesh, evt));
                            }
                            if (clickInfo.doubleClick && !clickInfo.ignore && pickResult.pickedMesh.actionManager.hasSpecificTrigger(ActionManager.OnDoublePickTrigger)) {
                                pickResult.pickedMesh.actionManager.processTrigger(ActionManager.OnDoublePickTrigger, ActionEvent.CreateNew(pickResult.pickedMesh, evt));
                            }
                        }
                    }
                    if (this._pickedDownMesh &&
                        this._pickedDownMesh.actionManager && 
                        this._pickedDownMesh.actionManager.hasSpecificTrigger(ActionManager.OnPickOutTrigger) &&
                        this._pickedDownMesh !== this._pickedUpMesh) {
                        this._pickedDownMesh.actionManager.processTrigger(ActionManager.OnPickOutTrigger, ActionEvent.CreateNew(this._pickedDownMesh, evt));
                    }

                    if (this.onPointerUp) {
                        this.onPointerUp(evt, pickResult);
                    }

                    if (this.onPointerObservable.hasObservers()) {
                        if (!clickInfo.ignore) {
                            if (!clickInfo.hasSwiped) {
                                if (clickInfo.singleClick && this.onPointerObservable.hasSpecificMask(PointerEventTypes.POINTERTAP)) {
                                    let type = PointerEventTypes.POINTERTAP;
                                    let pi = new PointerInfo(type, evt, pickResult);
                                    this.onPointerObservable.notifyObservers(pi, type);
                                }
                                if (clickInfo.doubleClick && this.onPointerObservable.hasSpecificMask(PointerEventTypes.POINTERDOUBLETAP)) {
                                    let type = PointerEventTypes.POINTERDOUBLETAP;
                                    let pi = new PointerInfo(type, evt, pickResult);
                                    this.onPointerObservable.notifyObservers(pi, type);
                                }
                            }
                        }
                        else {
                            let type = PointerEventTypes.POINTERUP;
                            let pi = new PointerInfo(type, evt, pickResult);
                            this.onPointerObservable.notifyObservers(pi, type);
                        }
                    }

                    // Sprites
                    if (this.spriteManagers.length > 0) {
                        pickResult = this.pickSprite(this._unTranslatedPointerX, this._unTranslatedPointerY, spritePredicate, false, this.cameraToUseForPointers);

                        if (pickResult.hit && pickResult.pickedSprite) {
                            if (pickResult.pickedSprite.actionManager) {
                                pickResult.pickedSprite.actionManager.processTrigger(ActionManager.OnPickUpTrigger, ActionEvent.CreateNewFromSprite(pickResult.pickedSprite, this, evt));
                                if (pickResult.pickedSprite.actionManager) {
                                    if (Math.abs(this._startingPointerPosition.x - this._pointerX) < Scene.DragMovementThreshold && Math.abs(this._startingPointerPosition.y - this._pointerY) < Scene.DragMovementThreshold) {
                                        pickResult.pickedSprite.actionManager.processTrigger(ActionManager.OnPickTrigger, ActionEvent.CreateNewFromSprite(pickResult.pickedSprite, this, evt));
                                    }
                                }
                            }
                        }
                        if (this._pickedDownSprite && this._pickedDownSprite.actionManager && this._pickedDownSprite !== pickResult.pickedSprite) {
                            this._pickedDownSprite.actionManager.processTrigger(ActionManager.OnPickOutTrigger, ActionEvent.CreateNewFromSprite(this._pickedDownSprite, this, evt));
                        }
                    }
                    this._previousPickResult = this._currentPickResult;
                }).bind(this));
            };

            this._onKeyDown = (evt: Event) => {
                if (this.actionManager) {
                    this.actionManager.processTrigger(ActionManager.OnKeyDownTrigger, ActionEvent.CreateNewFromScene(this, evt));
                }
            };

            this._onKeyUp = (evt: Event) => {
                if (this.actionManager) {
                    this.actionManager.processTrigger(ActionManager.OnKeyUpTrigger, ActionEvent.CreateNewFromScene(this, evt));
                }
            };


            var eventPrefix = Tools.GetPointerPrefix();
            var canvas = this._engine.getRenderingCanvas();
            if (attachMove) {
                canvas.addEventListener(eventPrefix + "move", this._onPointerMove, false);
                // Wheel
                canvas.addEventListener('mousewheel', this._onPointerMove, false);
                canvas.addEventListener('DOMMouseScroll', this._onPointerMove, false);
            }

            if (attachDown) {
                canvas.addEventListener(eventPrefix + "down", this._onPointerDown, false);
            }

            if (attachUp) {
                canvas.addEventListener(eventPrefix + "up", this._onPointerUp, false);
            }

            canvas.tabIndex = 1;

            canvas.addEventListener("keydown", this._onKeyDown, false);
            canvas.addEventListener("keyup", this._onKeyUp, false);
        }

        public detachControl() {
            var eventPrefix = Tools.GetPointerPrefix();
            var canvas = this._engine.getRenderingCanvas();

            canvas.removeEventListener(eventPrefix + "move", this._onPointerMove);
            canvas.removeEventListener(eventPrefix + "down", this._onPointerDown);
            canvas.removeEventListener(eventPrefix + "up", this._onPointerUp);

            // Wheel
            canvas.removeEventListener('mousewheel', this._onPointerMove);
            canvas.removeEventListener('DOMMouseScroll', this._onPointerMove);

            canvas.removeEventListener("keydown", this._onKeyDown);
            canvas.removeEventListener("keyup", this._onKeyUp);
        }

        // Ready
        public isReady(): boolean {
            if (this._pendingData.length > 0) {
                return false;
            }
            var index: number;

            // Geometries
            for (index = 0; index < this._geometries.length; index++) {
                var geometry = this._geometries[index];

                if (geometry.delayLoadState === Engine.DELAYLOADSTATE_LOADING) {
                    return false;
                }
            }

            // Meshes
            for (index = 0; index < this.meshes.length; index++) {
                var mesh = this.meshes[index];

                if (!mesh.isEnabled()) {
                    continue;
                }

                if (!mesh.subMeshes || mesh.subMeshes.length === 0) {
                    continue;
                }

                if (!mesh.isReady()) {
                    return false;
                }

                var mat = mesh.material;
                if (mat) {
                    if (!mat.isReady(mesh)) {
                        return false;
                    }
                }
            }

            return true;
        }

        public resetCachedMaterial(): void {
            this._cachedMaterial = null;
            this._cachedEffect = null;
            this._cachedVisibility = null;
        }

        public registerBeforeRender(func: () => void): void {
            this.onBeforeRenderObservable.add(func);
        }

        public unregisterBeforeRender(func: () => void): void {
            this.onBeforeRenderObservable.removeCallback(func);
        }

        public registerAfterRender(func: () => void): void {
            this.onAfterRenderObservable.add(func);
        }

        public unregisterAfterRender(func: () => void): void {
            this.onAfterRenderObservable.removeCallback(func);
        }

        public _addPendingData(data): void {
            this._pendingData.push(data);
        }

        public _removePendingData(data): void {
            var index = this._pendingData.indexOf(data);

            if (index !== -1) {
                this._pendingData.splice(index, 1);
            }
        }

        public getWaitingItemsCount(): number {
            return this._pendingData.length;
        }

        /**
         * Registers a function to be executed when the scene is ready.
         * @param {Function} func - the function to be executed.
         */
        public executeWhenReady(func: () => void): void {
            this.onReadyObservable.add(func);

            if (this._executeWhenReadyTimeoutId !== -1) {
                return;
            }

            this._executeWhenReadyTimeoutId = setTimeout(() => {
                this._checkIsReady();
            }, 150);
        }

        public _checkIsReady() {
            if (this.isReady()) {
                this.onReadyObservable.notifyObservers(this);

                this.onReadyObservable.clear();
                this._executeWhenReadyTimeoutId = -1;
                return;
            }

            this._executeWhenReadyTimeoutId = setTimeout(() => {
                this._checkIsReady();
            }, 150);
        }

        // Animations
        /**
         * Will start the animation sequence of a given target
         * @param target - the target 
         * @param {number} from - from which frame should animation start
         * @param {number} to - till which frame should animation run.
         * @param {boolean} [loop] - should the animation loop
         * @param {number} [speedRatio] - the speed in which to run the animation
         * @param {Function} [onAnimationEnd] function to be executed when the animation ended.
         * @param {BABYLON.Animatable} [animatable] an animatable object. If not provided a new one will be created from the given params.
         * @return {BABYLON.Animatable} the animatable object created for this animation
         * @see BABYLON.Animatable
         * @see http://doc.babylonjs.com/page.php?p=22081
         */
        public beginAnimation(target: any, from: number, to: number, loop?: boolean, speedRatio: number = 1.0, onAnimationEnd?: () => void, animatable?: Animatable): Animatable {

            if(from > to && speedRatio > 0){
                speedRatio *= -1;
            }

            this.stopAnimation(target);

            if (!animatable) {
                animatable = new Animatable(this, target, from, to, loop, speedRatio, onAnimationEnd);
            }

            // Local animations
            if (target.animations) {
                animatable.appendAnimations(target, target.animations);
            }

            // Children animations
            if (target.getAnimatables) {
                var animatables = target.getAnimatables();
                for (var index = 0; index < animatables.length; index++) {
                    this.beginAnimation(animatables[index], from, to, loop, speedRatio, onAnimationEnd, animatable);
                }
            }

            animatable.reset();

            return animatable;
        }

        public beginDirectAnimation(target: any, animations: Animation[], from: number, to: number, loop?: boolean, speedRatio?: number, onAnimationEnd?: () => void): Animatable {
            if (speedRatio === undefined) {
                speedRatio = 1.0;
            }

            var animatable = new Animatable(this, target, from, to, loop, speedRatio, onAnimationEnd, animations);

            return animatable;
        }

        public getAnimatableByTarget(target: any): Animatable {
            for (var index = 0; index < this._activeAnimatables.length; index++) {
                if (this._activeAnimatables[index].target === target) {
                    return this._activeAnimatables[index];
                }
            }

            return null;
        }

        public get Animatables(): Animatable[] {
            return this._activeAnimatables;
        }

        /**
         * Will stop the animation of the given target
         * @param target - the target 
         * @param animationName - the name of the animation to stop (all animations will be stopped is empty)
         * @see beginAnimation
         */
        public stopAnimation(target: any, animationName?: string): void {
            var animatable = this.getAnimatableByTarget(target);

            if (animatable) {
                animatable.stop(animationName);
            }
        }

        private _animate(): void {
            if (!this.animationsEnabled || this._activeAnimatables.length === 0) {
                return;
            }

            // Getting time
            var now = Tools.Now;
            if (!this._animationTimeLast) {
                if (this._pendingData.length > 0) {
                    return;
                }
                this._animationTimeLast = now;
            }
            var deltaTime = (now - this._animationTimeLast) * this.animationTimeScale;
            this._animationTime += deltaTime;
            this._animationTimeLast = now;
            for (var index = 0; index < this._activeAnimatables.length; index++) {
                this._activeAnimatables[index]._animate(this._animationTime);
            }
        }

        // Matrix
        public getViewMatrix(): Matrix {
            return this._viewMatrix;
        }

        public getProjectionMatrix(): Matrix {
            return this._projectionMatrix;
        }

        public getTransformMatrix(): Matrix {
            return this._transformMatrix;
        }

        public setTransformMatrix(view: Matrix, projection: Matrix): void {
            if (this._viewUpdateFlag === view.updateFlag && this._projectionUpdateFlag === projection.updateFlag) {
                return;
            }

            this._viewUpdateFlag = view.updateFlag;
            this._projectionUpdateFlag = projection.updateFlag;
            this._viewMatrix = view;
            this._projectionMatrix = projection;

            this._viewMatrix.multiplyToRef(this._projectionMatrix, this._transformMatrix);

            // Update frustum
            if (!this._frustumPlanes) {
                this._frustumPlanes = Frustum.GetPlanes(this._transformMatrix);
            } else {
                Frustum.GetPlanesToRef(this._transformMatrix, this._frustumPlanes);
            }

            if (this._sceneUbo.useUbo) {
                this._sceneUbo.updateMatrix("viewProjection", this._transformMatrix);
                this._sceneUbo.updateMatrix("view", this._viewMatrix);
                this._sceneUbo.update();
            }
        }

        public getSceneUniformBuffer(): UniformBuffer {
            return this._sceneUbo;
        }

        // Methods

        public getUniqueId() {
            var result = this._uniqueIdCounter;
            this._uniqueIdCounter++;
            return result;
        }

        public addMesh(newMesh: AbstractMesh) {
            newMesh.uniqueId = this.getUniqueId();
            var position = this.meshes.push(newMesh);

            //notify the collision coordinator
            if (this.collisionCoordinator) {
                this.collisionCoordinator.onMeshAdded(newMesh);
            }

            this.onNewMeshAddedObservable.notifyObservers(newMesh);
        }

        public removeMesh(toRemove: AbstractMesh): number {
            var index = this.meshes.indexOf(toRemove);
            if (index !== -1) {
                // Remove from the scene if mesh found 
                this.meshes.splice(index, 1);
            }
            //notify the collision coordinator
            if (this.collisionCoordinator) {
                this.collisionCoordinator.onMeshRemoved(toRemove);
            }

            this.onMeshRemovedObservable.notifyObservers(toRemove);

            return index;
        }

        public removeSkeleton(toRemove: Skeleton): number {
            var index = this.skeletons.indexOf(toRemove);
            if (index !== -1) {
                // Remove from the scene if found 
                this.skeletons.splice(index, 1);
            }

            return index;
        }

        public removeMorphTargetManager(toRemove: MorphTargetManager): number {
            var index = this.morphTargetManagers.indexOf(toRemove);
            if (index !== -1) {
                // Remove from the scene if found 
                this.morphTargetManagers.splice(index, 1);
            }

            return index;
        }

        public removeLight(toRemove: Light): number {
            var index = this.lights.indexOf(toRemove);
            if (index !== -1) {
                // Remove from the scene if mesh found 
                this.lights.splice(index, 1);
                this.sortLightsByPriority();
            }
            this.onLightRemovedObservable.notifyObservers(toRemove);
            return index;
        }

        public removeCamera(toRemove: Camera): number {
            var index = this.cameras.indexOf(toRemove);
            if (index !== -1) {
                // Remove from the scene if mesh found 
                this.cameras.splice(index, 1);
            }
            // Remove from activeCameras
            var index2 = this.activeCameras.indexOf(toRemove);
            if (index2 !== -1) {
                // Remove from the scene if mesh found
                this.activeCameras.splice(index2, 1);
            }
            // Reset the activeCamera
            if (this.activeCamera === toRemove) {
                if (this.cameras.length > 0) {
                    this.activeCamera = this.cameras[0];
                } else {
                    this.activeCamera = null;
                }
            }
            this.onCameraRemovedObservable.notifyObservers(toRemove);
            return index;
        }

        public addLight(newLight: Light) {
            newLight.uniqueId = this.getUniqueId();
            this.lights.push(newLight);
            this.sortLightsByPriority();

            this.onNewLightAddedObservable.notifyObservers(newLight);
        }

        public sortLightsByPriority(): void {
            if(this.requireLightSorting) {
                this.lights.sort(Light.compareLightsPriority);
            }
        }

        public addCamera(newCamera: Camera) {
            newCamera.uniqueId = this.getUniqueId();
            var position = this.cameras.push(newCamera);
            this.onNewCameraAddedObservable.notifyObservers(newCamera);
        }

        /**
         * Switch active camera
         * @param {Camera} newCamera - new active camera
		 * @param {boolean} attachControl - call attachControl for the new active camera (default: true)
         */
        public switchActiveCamera(newCamera: Camera, attachControl = true) {
            var canvas = this._engine.getRenderingCanvas();
            this.activeCamera.detachControl(canvas);
            this.activeCamera = newCamera;
            if (attachControl) {
                newCamera.attachControl(canvas);
            }
        }

        /**
         * sets the active camera of the scene using its ID
         * @param {string} id - the camera's ID
         * @return {BABYLON.Camera|null} the new active camera or null if none found.
         * @see activeCamera
         */
        public setActiveCameraByID(id: string): Camera {
            var camera = this.getCameraByID(id);

            if (camera) {
                this.activeCamera = camera;
                return camera;
            }

            return null;
        }

        /**
         * sets the active camera of the scene using its name
         * @param {string} name - the camera's name
         * @return {BABYLON.Camera|null} the new active camera or null if none found.
         * @see activeCamera
         */
        public setActiveCameraByName(name: string): Camera {
            var camera = this.getCameraByName(name);

            if (camera) {
                this.activeCamera = camera;
                return camera;
            }

            return null;
        }

        /**
         * get a material using its id
         * @param {string} the material's ID
         * @return {BABYLON.Material|null} the material or null if none found.
         */
        public getMaterialByID(id: string): Material {
            for (var index = 0; index < this.materials.length; index++) {
                if (this.materials[index].id === id) {
                    return this.materials[index];
                }
            }

            return null;
        }

        /**
         * get a material using its name
         * @param {string} the material's name
         * @return {BABYLON.Material|null} the material or null if none found.
         */
        public getMaterialByName(name: string): Material {
            for (var index = 0; index < this.materials.length; index++) {
                if (this.materials[index].name === name) {
                    return this.materials[index];
                }
            }

            return null;
        }

        public getLensFlareSystemByName(name: string): LensFlareSystem {
            for (var index = 0; index < this.lensFlareSystems.length; index++) {
                if (this.lensFlareSystems[index].name === name) {
                    return this.lensFlareSystems[index];
                }
            }

            return null;
        }

        public getLensFlareSystemByID(id: string): LensFlareSystem {
            for (var index = 0; index < this.lensFlareSystems.length; index++) {
                if (this.lensFlareSystems[index].id === id) {
                    return this.lensFlareSystems[index];
                }
            }

            return null;
        }

        public getCameraByID(id: string): Camera {
            for (var index = 0; index < this.cameras.length; index++) {
                if (this.cameras[index].id === id) {
                    return this.cameras[index];
                }
            }

            return null;
        }

        public getCameraByUniqueID(uniqueId: number): Camera {
            for (var index = 0; index < this.cameras.length; index++) {
                if (this.cameras[index].uniqueId === uniqueId) {
                    return this.cameras[index];
                }
            }

            return null;
        }

        /**
         * get a camera using its name
         * @param {string} the camera's name
         * @return {BABYLON.Camera|null} the camera or null if none found.
         */
        public getCameraByName(name: string): Camera {
            for (var index = 0; index < this.cameras.length; index++) {
                if (this.cameras[index].name === name) {
                    return this.cameras[index];
                }
            }

            return null;
        }

        /**
         * get a bone using its id
         * @param {string} the bone's id
         * @return {BABYLON.Bone|null} the bone or null if not found
         */
        public getBoneByID(id: string): Bone {
            for (var skeletonIndex = 0; skeletonIndex < this.skeletons.length; skeletonIndex++) {
                var skeleton = this.skeletons[skeletonIndex];
                for (var boneIndex = 0; boneIndex < skeleton.bones.length; boneIndex++) {
                    if (skeleton.bones[boneIndex].id === id) {
                        return skeleton.bones[boneIndex];
                    }
                }
            }

            return null;
        }

        /**
        * get a bone using its id
        * @param {string} the bone's name
        * @return {BABYLON.Bone|null} the bone or null if not found
        */
        public getBoneByName(name: string): Bone {
            for (var skeletonIndex = 0; skeletonIndex < this.skeletons.length; skeletonIndex++) {
                var skeleton = this.skeletons[skeletonIndex];
                for (var boneIndex = 0; boneIndex < skeleton.bones.length; boneIndex++) {
                    if (skeleton.bones[boneIndex].name === name) {
                        return skeleton.bones[boneIndex];
                    }
                }
            }

            return null;
        }

        /**
         * get a light node using its name
         * @param {string} the light's name
         * @return {BABYLON.Light|null} the light or null if none found.
         */
        public getLightByName(name: string): Light {
            for (var index = 0; index < this.lights.length; index++) {
                if (this.lights[index].name === name) {
                    return this.lights[index];
                }
            }

            return null;
        }

        /**
         * get a light node using its ID
         * @param {string} the light's id
         * @return {BABYLON.Light|null} the light or null if none found.
         */
        public getLightByID(id: string): Light {
            for (var index = 0; index < this.lights.length; index++) {
                if (this.lights[index].id === id) {
                    return this.lights[index];
                }
            }

            return null;
        }

        /**
         * get a light node using its scene-generated unique ID
         * @param {number} the light's unique id
         * @return {BABYLON.Light|null} the light or null if none found.
         */
        public getLightByUniqueID(uniqueId: number): Light {
            for (var index = 0; index < this.lights.length; index++) {
                if (this.lights[index].uniqueId === uniqueId) {
                    return this.lights[index];
                }
            }

            return null;
        }


        /**
         * get a particle system by id
         * @param id {number} the particle system id
         * @return {BABYLON.ParticleSystem|null} the corresponding system or null if none found.
         */
        public getParticleSystemByID(id: string): ParticleSystem {
            for (var index = 0; index < this.particleSystems.length; index++) {
                if (this.particleSystems[index].id === id) {
                    return this.particleSystems[index];
                }
            }

            return null;
        }

        /**
         * get a geometry using its ID
         * @param {string} the geometry's id
         * @return {BABYLON.Geometry|null} the geometry or null if none found.
         */
        public getGeometryByID(id: string): Geometry {
            for (var index = 0; index < this._geometries.length; index++) {
                if (this._geometries[index].id === id) {
                    return this._geometries[index];
                }
            }

            return null;
        }

        /**
         * add a new geometry to this scene.
         * @param {BABYLON.Geometry} geometry - the geometry to be added to the scene.
         * @param {boolean} [force] - force addition, even if a geometry with this ID already exists
         * @return {boolean} was the geometry added or not
         */
        public pushGeometry(geometry: Geometry, force?: boolean): boolean {
            if (!force && this.getGeometryByID(geometry.id)) {
                return false;
            }

            this._geometries.push(geometry);

            //notify the collision coordinator
            if (this.collisionCoordinator) {
                this.collisionCoordinator.onGeometryAdded(geometry);
            }

            this.onNewGeometryAddedObservable.notifyObservers(geometry);

            return true;
        }

        /**
         * Removes an existing geometry
         * @param {BABYLON.Geometry} geometry - the geometry to be removed from the scene.
         * @return {boolean} was the geometry removed or not
         */
        public removeGeometry(geometry: Geometry): boolean {
            var index = this._geometries.indexOf(geometry);

            if (index > -1) {
                this._geometries.splice(index, 1);

                //notify the collision coordinator
                if (this.collisionCoordinator) {
                    this.collisionCoordinator.onGeometryDeleted(geometry);
                }

                this.onGeometryRemovedObservable.notifyObservers(geometry);
                return true;
            }
            return false;
        }

        public getGeometries(): Geometry[] {
            return this._geometries;
        }

        /**
         * Get the first added mesh found of a given ID
         * @param {string} id - the id to search for
         * @return {BABYLON.AbstractMesh|null} the mesh found or null if not found at all.
         */
        public getMeshByID(id: string): AbstractMesh {
            for (var index = 0; index < this.meshes.length; index++) {
                if (this.meshes[index].id === id) {
                    return this.meshes[index];
                }
            }

            return null;
        }

        public getMeshesByID(id: string): Array<AbstractMesh> {
            return this.meshes.filter(function (m) {
                return m.id === id;
            })
        }

        /**
         * Get a mesh with its auto-generated unique id
         * @param {number} uniqueId - the unique id to search for
         * @return {BABYLON.AbstractMesh|null} the mesh found or null if not found at all.
         */
        public getMeshByUniqueID(uniqueId: number): AbstractMesh {
            for (var index = 0; index < this.meshes.length; index++) {
                if (this.meshes[index].uniqueId === uniqueId) {
                    return this.meshes[index];
                }
            }

            return null;
        }

        /**
         * Get a the last added mesh found of a given ID
         * @param {string} id - the id to search for
         * @return {BABYLON.AbstractMesh|null} the mesh found or null if not found at all.
         */
        public getLastMeshByID(id: string): AbstractMesh {
            for (var index = this.meshes.length - 1; index >= 0; index--) {
                if (this.meshes[index].id === id) {
                    return this.meshes[index];
                }
            }

            return null;
        }

        /**
         * Get a the last added node (Mesh, Camera, Light) found of a given ID
         * @param {string} id - the id to search for
         * @return {BABYLON.Node|null} the node found or null if not found at all.
         */
        public getLastEntryByID(id: string): Node {
            var index: number;
            for (index = this.meshes.length - 1; index >= 0; index--) {
                if (this.meshes[index].id === id) {
                    return this.meshes[index];
                }
            }

            for (index = this.cameras.length - 1; index >= 0; index--) {
                if (this.cameras[index].id === id) {
                    return this.cameras[index];
                }
            }

            for (index = this.lights.length - 1; index >= 0; index--) {
                if (this.lights[index].id === id) {
                    return this.lights[index];
                }
            }

            return null;
        }

        public getNodeByID(id: string): Node {
            var mesh = this.getMeshByID(id);

            if (mesh) {
                return mesh;
            }

            var light = this.getLightByID(id);

            if (light) {
                return light;
            }

            var camera = this.getCameraByID(id);

            if (camera) {
                return camera;
            }

            var bone = this.getBoneByID(id);

            return bone;
        }

        public getNodeByName(name: string): Node {
            var mesh = this.getMeshByName(name);

            if (mesh) {
                return mesh;
            }

            var light = this.getLightByName(name);

            if (light) {
                return light;
            }

            var camera = this.getCameraByName(name);

            if (camera) {
                return camera;
            }

            var bone = this.getBoneByName(name);

            return bone;
        }

        public getMeshByName(name: string): AbstractMesh {
            for (var index = 0; index < this.meshes.length; index++) {
                if (this.meshes[index].name === name) {
                    return this.meshes[index];
                }
            }

            return null;
        }

        public getSoundByName(name: string): Sound {
            var index: number;
            if (AudioEngine) {
                for (index = 0; index < this.mainSoundTrack.soundCollection.length; index++) {
                    if (this.mainSoundTrack.soundCollection[index].name === name) {
                        return this.mainSoundTrack.soundCollection[index];
                    }
                }

                for (var sdIndex = 0; sdIndex < this.soundTracks.length; sdIndex++) {
                    for (index = 0; index < this.soundTracks[sdIndex].soundCollection.length; index++) {
                        if (this.soundTracks[sdIndex].soundCollection[index].name === name) {
                            return this.soundTracks[sdIndex].soundCollection[index];
                        }
                    }
                }
            }

            return null;
        }

        public getLastSkeletonByID(id: string): Skeleton {
            for (var index = this.skeletons.length - 1; index >= 0; index--) {
                if (this.skeletons[index].id === id) {
                    return this.skeletons[index];
                }
            }

            return null;
        }

        public getSkeletonById(id: string): Skeleton {
            for (var index = 0; index < this.skeletons.length; index++) {
                if (this.skeletons[index].id === id) {
                    return this.skeletons[index];
                }
            }

            return null;
        }

        public getSkeletonByName(name: string): Skeleton {
            for (var index = 0; index < this.skeletons.length; index++) {
                if (this.skeletons[index].name === name) {
                    return this.skeletons[index];
                }
            }

            return null;
        }

        public getMorphTargetManagerById(id: number): MorphTargetManager {
            for (var index = 0; index < this.morphTargetManagers.length; index++) {
                if (this.morphTargetManagers[index].uniqueId === id) {
                    return this.morphTargetManagers[index];
                }
            }

            return null;
        }

        public isActiveMesh(mesh: Mesh): boolean {
            return (this._activeMeshes.indexOf(mesh) !== -1);
        }

        /**
         * Return a the first highlight layer of the scene with a given name.
         * @param name The name of the highlight layer to look for.
         * @return The highlight layer if found otherwise null. 
         */
        public getHighlightLayerByName(name: string): HighlightLayer {
            for (var index = 0; index < this.highlightLayers.length; index++) {
                if (this.highlightLayers[index].name === name) {
                    return this.highlightLayers[index];
                }
            }

            return null;
        }

        /**
         * Return a unique id as a string which can serve as an identifier for the scene
         */
        public get uid(): string {
            if (!this._uid) {
                this._uid = Tools.RandomId();
            }
            return this._uid;
        }

        /**
         * Add an externaly attached data from its key.
         * This method call will fail and return false, if such key already exists.
         * If you don't care and just want to get the data no matter what, use the more convenient getOrAddExternalDataWithFactory() method.
         * @param key the unique key that identifies the data
         * @param data the data object to associate to the key for this Engine instance
         * @return true if no such key were already present and the data was added successfully, false otherwise
         */
        public addExternalData<T>(key: string, data: T): boolean {
            if (!this._externalData) {
                this._externalData = new StringDictionary<Object>();
            }
            return this._externalData.add(key, data);
        }

        /**
         * Get an externaly attached data from its key
         * @param key the unique key that identifies the data
         * @return the associated data, if present (can be null), or undefined if not present
         */
        public getExternalData<T>(key: string): T {
            if (!this._externalData) {
                return null;
            }
            return <T>this._externalData.get(key);
        }

        /**
         * Get an externaly attached data from its key, create it using a factory if it's not already present
         * @param key the unique key that identifies the data
         * @param factory the factory that will be called to create the instance if and only if it doesn't exists
         * @return the associated data, can be null if the factory returned null.
         */
        public getOrAddExternalDataWithFactory<T>(key: string, factory: (k: string) => T): T {
            if (!this._externalData) {
                this._externalData = new StringDictionary<Object>();
            }
            return <T>this._externalData.getOrAddWithFactory(key, factory);
        }

        /**
         * Remove an externaly attached data from the Engine instance
         * @param key the unique key that identifies the data
         * @return true if the data was successfully removed, false if it doesn't exist
         */
        public removeExternalData(key): boolean {
            return this._externalData.remove(key);
        }

        private _evaluateSubMesh(subMesh: SubMesh, mesh: AbstractMesh): void {
            if (mesh.alwaysSelectAsActiveMesh || mesh.subMeshes.length === 1 || subMesh.isInFrustum(this._frustumPlanes)) {
                var material = subMesh.getMaterial();

                if (mesh.showSubMeshesBoundingBox) {
                    this.getBoundingBoxRenderer().renderList.push(subMesh.getBoundingInfo().boundingBox);
                }

                if (material) {
                    // Render targets
                    if (material.getRenderTargetTextures) {
                        if (this._processedMaterials.indexOf(material) === -1) {
                            this._processedMaterials.push(material);

                            this._renderTargets.concatWithNoDuplicate(material.getRenderTargetTextures());
                        }
                    }

                    // Dispatch
                    this._activeIndices.addCount(subMesh.indexCount, false);
                    this._renderingManager.dispatch(subMesh);
                }
            }
        }

        public _isInIntermediateRendering(): boolean {
            return this._intermediateRendering
        }

        private _evaluateActiveMeshes(): void {
            this.activeCamera._activeMeshes.reset();
            this._activeMeshes.reset();
            this._renderingManager.reset();
            this._processedMaterials.reset();
            this._activeParticleSystems.reset();
            this._activeSkeletons.reset();
            this._softwareSkinnedMeshes.reset();
            if (this._boundingBoxRenderer) {
                this._boundingBoxRenderer.reset();
            }

            // Meshes
            var meshes: AbstractMesh[];
            var len: number;

            if (this._selectionOctree) { // Octree
                var selection = this._selectionOctree.select(this._frustumPlanes);
                meshes = selection.data;
                len = selection.length;
            } else { // Full scene traversal
                len = this.meshes.length;
                meshes = this.meshes;
            }

            for (var meshIndex = 0; meshIndex < len; meshIndex++) {
                var mesh = meshes[meshIndex];

                if (mesh.isBlocked) {
                    continue;
                }

                this._totalVertices.addCount(mesh.getTotalVertices(), false);

                if (!mesh.isReady() || !mesh.isEnabled()) {
                    continue;
                }

                mesh.computeWorldMatrix();

                // Intersections
                if (mesh.actionManager && mesh.actionManager.hasSpecificTriggers([ActionManager.OnIntersectionEnterTrigger, ActionManager.OnIntersectionExitTrigger])) {
                    this._meshesForIntersections.pushNoDuplicate(mesh);
                }

                // Switch to current LOD
                var meshLOD = mesh.getLOD(this.activeCamera);

                if (!meshLOD) {
                    continue;
                }

                mesh._preActivate();

                if (mesh.alwaysSelectAsActiveMesh || mesh.isVisible && mesh.visibility > 0 && ((mesh.layerMask & this.activeCamera.layerMask) !== 0) && mesh.isInFrustum(this._frustumPlanes)) {
                    this._activeMeshes.push(mesh);
                    this.activeCamera._activeMeshes.push(mesh);
                    mesh._activate(this._renderId);

                    this._activeMesh(mesh, meshLOD);
                }
            }

            // Particle systems
            this._particlesDuration.beginMonitoring();
            var beforeParticlesDate = Tools.Now;
            if (this.particlesEnabled) {
                Tools.StartPerformanceCounter("Particles", this.particleSystems.length > 0);
                for (var particleIndex = 0; particleIndex < this.particleSystems.length; particleIndex++) {
                    var particleSystem = this.particleSystems[particleIndex];

                    if (!particleSystem.isStarted()) {
                        continue;
                    }

                    if (!particleSystem.emitter.position || (particleSystem.emitter && particleSystem.emitter.isEnabled())) {
                        this._activeParticleSystems.push(particleSystem);
                        particleSystem.animate();
                        this._renderingManager.dispatchParticles(particleSystem);
                    }
                }
                Tools.EndPerformanceCounter("Particles", this.particleSystems.length > 0);
            }
            this._particlesDuration.endMonitoring(false);
        }

        private _activeMesh(sourceMesh: AbstractMesh, mesh: AbstractMesh): void {
            if (mesh.skeleton && this.skeletonsEnabled) {
                if (this._activeSkeletons.pushNoDuplicate(mesh.skeleton)) {
                    mesh.skeleton.prepare();
                }

                if (!mesh.computeBonesUsingShaders) {
                    this._softwareSkinnedMeshes.pushNoDuplicate(mesh);
                }
            }

            if (sourceMesh.showBoundingBox || this.forceShowBoundingBoxes) {
                this.getBoundingBoxRenderer().renderList.push(sourceMesh.getBoundingInfo().boundingBox);
            }

            if (mesh && mesh.subMeshes) {
                // Submeshes Octrees
                var len: number;
                var subMeshes: SubMesh[];

                if (mesh._submeshesOctree && mesh.useOctreeForRenderingSelection) {
                    var intersections = mesh._submeshesOctree.select(this._frustumPlanes);

                    len = intersections.length;
                    subMeshes = intersections.data;
                } else {
                    subMeshes = mesh.subMeshes;
                    len = subMeshes.length;
                }

                for (var subIndex = 0; subIndex < len; subIndex++) {
                    var subMesh = subMeshes[subIndex];

                    this._evaluateSubMesh(subMesh, mesh);
                }
            }
        }

        public updateTransformMatrix(force?: boolean): void {
            this.setTransformMatrix(this.activeCamera.getViewMatrix(), this.activeCamera.getProjectionMatrix(force));
        }

        private _renderForCamera(camera: Camera): void {
            var engine = this._engine;
            var startTime = Tools.Now;

            this.activeCamera = camera;

            if (!this.activeCamera)
                throw new Error("Active camera not set");

            Tools.StartPerformanceCounter("Rendering camera " + this.activeCamera.name);

            // Viewport
            engine.setViewport(this.activeCamera.viewport);

            // Camera
            this.resetCachedMaterial();
            this._renderId++;
            this.updateTransformMatrix();

            this.onBeforeCameraRenderObservable.notifyObservers(this.activeCamera);

            // Meshes
            this._evaluateActiveMeshesDuration.beginMonitoring();
            Tools.StartPerformanceCounter("Active meshes evaluation");
            this._evaluateActiveMeshes();
            this._evaluateActiveMeshesDuration.endMonitoring(false);
            Tools.EndPerformanceCounter("Active meshes evaluation");

            // Software skinning
            for (var softwareSkinnedMeshIndex = 0; softwareSkinnedMeshIndex < this._softwareSkinnedMeshes.length; softwareSkinnedMeshIndex++) {
                var mesh = this._softwareSkinnedMeshes.data[softwareSkinnedMeshIndex];

                mesh.applySkeleton(mesh.skeleton);
            }

            // Render targets
            this._renderTargetsDuration.beginMonitoring();
            var needsRestoreFrameBuffer = false;

            var beforeRenderTargetDate = Tools.Now;

            if (camera.customRenderTargets && camera.customRenderTargets.length > 0) {
                this._renderTargets.concatWithNoDuplicate(camera.customRenderTargets);
            }

            if (this.renderTargetsEnabled && this._renderTargets.length > 0) {
                this._intermediateRendering = true;
                Tools.StartPerformanceCounter("Render targets", this._renderTargets.length > 0);
                for (var renderIndex = 0; renderIndex < this._renderTargets.length; renderIndex++) {
                    let renderTarget = this._renderTargets.data[renderIndex];
                    if (renderTarget._shouldRender()) {
                        this._renderId++;
                        var hasSpecialRenderTargetCamera = renderTarget.activeCamera && renderTarget.activeCamera !== this.activeCamera;
                        renderTarget.render(hasSpecialRenderTargetCamera, this.dumpNextRenderTargets);
                    }
                }
                Tools.EndPerformanceCounter("Render targets", this._renderTargets.length > 0);

                this._intermediateRendering = false;
                this._renderId++;

                needsRestoreFrameBuffer = true; // Restore back buffer
            }

            // Render HighlightLayer Texture
            var stencilState = this._engine.getStencilBuffer();
            var renderhighlights = false;
            if (this.renderTargetsEnabled && this.highlightLayers && this.highlightLayers.length > 0) {
                this._intermediateRendering = true;
                for (let i = 0; i < this.highlightLayers.length; i++) {
                    let highlightLayer = this.highlightLayers[i];

                    if (highlightLayer.shouldRender() &&
                        (!highlightLayer.camera ||
                            (highlightLayer.camera.cameraRigMode === Camera.RIG_MODE_NONE && camera === highlightLayer.camera) ||
                            (highlightLayer.camera.cameraRigMode !== Camera.RIG_MODE_NONE && highlightLayer.camera._rigCameras.indexOf(camera) > -1))) {

                        renderhighlights = true;

                        let renderTarget = (<RenderTargetTexture>(<any>highlightLayer)._mainTexture);
                        if (renderTarget._shouldRender()) {
                            this._renderId++;
                            renderTarget.render(false, false);
                            needsRestoreFrameBuffer = true;
                        }
                    }
                }

                this._intermediateRendering = false;
                this._renderId++;
            }

            if (needsRestoreFrameBuffer) {
                engine.restoreDefaultFramebuffer(); // Restore back buffer
            }

            this._renderTargetsDuration.endMonitoring(false);

            // Prepare Frame
            this.postProcessManager._prepareFrame();

            this._renderDuration.beginMonitoring();

            // Backgrounds
            var layerIndex;
            var layer;
            if (this.layers.length) {
                engine.setDepthBuffer(false);
                for (layerIndex = 0; layerIndex < this.layers.length; layerIndex++) {
                    layer = this.layers[layerIndex];
                    if (layer.isBackground && ((layer.layerMask & this.activeCamera.layerMask) !== 0)) {
                        layer.render();
                    }
                }
                engine.setDepthBuffer(true);
            }

            // Render
            Tools.StartPerformanceCounter("Main render");

            // Activate HighlightLayer stencil
            if (renderhighlights) {
                this._engine.setStencilBuffer(true);
            }

            this._renderingManager.render(null, null, true, true);

            // Restore HighlightLayer stencil
            if (renderhighlights) {
                this._engine.setStencilBuffer(stencilState);
            }

            Tools.EndPerformanceCounter("Main render");

            // Bounding boxes
            if (this._boundingBoxRenderer) {
                this._boundingBoxRenderer.render();
            }

            // Lens flares
            if (this.lensFlaresEnabled) {
                Tools.StartPerformanceCounter("Lens flares", this.lensFlareSystems.length > 0);
                for (var lensFlareSystemIndex = 0; lensFlareSystemIndex < this.lensFlareSystems.length; lensFlareSystemIndex++) {

                    var lensFlareSystem = this.lensFlareSystems[lensFlareSystemIndex];
                    if ((camera.layerMask & lensFlareSystem.layerMask) !== 0) {
                        lensFlareSystem.render();
                    }
                }
                Tools.EndPerformanceCounter("Lens flares", this.lensFlareSystems.length > 0);
            }

            // Foregrounds
            if (this.layers.length) {
                engine.setDepthBuffer(false);
                for (layerIndex = 0; layerIndex < this.layers.length; layerIndex++) {
                    layer = this.layers[layerIndex];
                    if (!layer.isBackground && ((layer.layerMask & this.activeCamera.layerMask) !== 0)) {
                        layer.render();
                    }
                }
                engine.setDepthBuffer(true);
            }

            // Highlight Layer
            if (renderhighlights) {
                engine.setDepthBuffer(false);
                for (let i = 0; i < this.highlightLayers.length; i++) {
                    if (this.highlightLayers[i].shouldRender()) {
                        this.highlightLayers[i].render();
                    }
                }
                engine.setDepthBuffer(true);
            }

            this._renderDuration.endMonitoring(false);

            // Finalize frame
            this.postProcessManager._finalizeFrame(camera.isIntermediate);

            // Update camera
            this.activeCamera._updateFromScene();

            // Reset some special arrays
            this._renderTargets.reset();

            this.onAfterCameraRenderObservable.notifyObservers(this.activeCamera);

            Tools.EndPerformanceCounter("Rendering camera " + this.activeCamera.name);
        }

        private _processSubCameras(camera: Camera): void {
            if (camera.cameraRigMode === Camera.RIG_MODE_NONE) {
                this._renderForCamera(camera);
                return;
            }

            // rig cameras
            for (var index = 0; index < camera._rigCameras.length; index++) {
                this._renderForCamera(camera._rigCameras[index]);
            }

            this.activeCamera = camera;
            this.setTransformMatrix(this.activeCamera.getViewMatrix(), this.activeCamera.getProjectionMatrix());

            // Update camera
            this.activeCamera._updateFromScene();
        }

        private _checkIntersections(): void {
            for (var index = 0; index < this._meshesForIntersections.length; index++) {
                var sourceMesh = this._meshesForIntersections.data[index];

                for (var actionIndex = 0; actionIndex < sourceMesh.actionManager.actions.length; actionIndex++) {
                    var action = sourceMesh.actionManager.actions[actionIndex];

                    if (action.trigger === ActionManager.OnIntersectionEnterTrigger || action.trigger === ActionManager.OnIntersectionExitTrigger) {
                        var parameters = action.getTriggerParameter();
                        var otherMesh = parameters instanceof AbstractMesh ? parameters : parameters.mesh;

                        var areIntersecting = otherMesh.intersectsMesh(sourceMesh, parameters.usePreciseIntersection);
                        var currentIntersectionInProgress = sourceMesh._intersectionsInProgress.indexOf(otherMesh);

                        if (areIntersecting && currentIntersectionInProgress === -1) {
                            if (action.trigger === ActionManager.OnIntersectionEnterTrigger) {
                                action._executeCurrent(ActionEvent.CreateNew(sourceMesh, null, otherMesh));
                                sourceMesh._intersectionsInProgress.push(otherMesh);
                            } else if (action.trigger === ActionManager.OnIntersectionExitTrigger) {
                                sourceMesh._intersectionsInProgress.push(otherMesh);
                            }
                        } else if (!areIntersecting && currentIntersectionInProgress > -1) {
                            //They intersected, and now they don't.

                            //is this trigger an exit trigger? execute an event.
                            if (action.trigger === ActionManager.OnIntersectionExitTrigger) {
                                action._executeCurrent(ActionEvent.CreateNew(sourceMesh, null, otherMesh));
                            }

                            //if this is an exit trigger, or no exit trigger exists, remove the id from the intersection in progress array.
                            if (!sourceMesh.actionManager.hasSpecificTrigger(ActionManager.OnIntersectionExitTrigger) || action.trigger === ActionManager.OnIntersectionExitTrigger) {
                                sourceMesh._intersectionsInProgress.splice(currentIntersectionInProgress, 1);
                            }
                        }
                    }
                }
            }
        }

        public render(): void {
            if (this.isDisposed) {
                return;
            }

            this._lastFrameDuration.beginMonitoring();
            this._particlesDuration.fetchNewFrame();
            this._spritesDuration.fetchNewFrame();
            this._activeParticles.fetchNewFrame();
            this._renderDuration.fetchNewFrame();
            this._renderTargetsDuration.fetchNewFrame();
            this._evaluateActiveMeshesDuration.fetchNewFrame();
            this._totalVertices.fetchNewFrame();
            this._activeIndices.fetchNewFrame();
            this._activeBones.fetchNewFrame();
            this.getEngine().drawCallsPerfCounter.fetchNewFrame();
            this._meshesForIntersections.reset();
            this.resetCachedMaterial();

            Tools.StartPerformanceCounter("Scene rendering");

            // Actions
            if (this.actionManager) {
                this.actionManager.processTrigger(ActionManager.OnEveryFrameTrigger, null);
            }

            //Simplification Queue
            if (this.simplificationQueue && !this.simplificationQueue.running) {
                this.simplificationQueue.executeNext();
            }

            // Animations
            var deltaTime = Math.max(Scene.MinDeltaTime, Math.min(this._engine.getDeltaTime(), Scene.MaxDeltaTime));
            this._animationRatio = deltaTime * (60.0 / 1000.0);
            this._animate();

            // Physics
            if (this._physicsEngine) {
               Tools.StartPerformanceCounter("Physics");
               this._physicsEngine._step(deltaTime / 1000.0);
               Tools.EndPerformanceCounter("Physics");
            }

            // Before render
            this.onBeforeRenderObservable.notifyObservers(this);

            // Customs render targets
            this._renderTargetsDuration.beginMonitoring();
            var beforeRenderTargetDate = Tools.Now;
            var engine = this.getEngine();
            var currentActiveCamera = this.activeCamera;
            if (this.renderTargetsEnabled) {
                Tools.StartPerformanceCounter("Custom render targets", this.customRenderTargets.length > 0);
                for (var customIndex = 0; customIndex < this.customRenderTargets.length; customIndex++) {
                    var renderTarget = this.customRenderTargets[customIndex];
                    if (renderTarget._shouldRender()) {
                        this._renderId++;

                        this.activeCamera = renderTarget.activeCamera || this.activeCamera;

                        if (!this.activeCamera)
                            throw new Error("Active camera not set");

                        // Viewport
                        engine.setViewport(this.activeCamera.viewport);

                        // Camera
                        this.updateTransformMatrix();

                        renderTarget.render(currentActiveCamera !== this.activeCamera, this.dumpNextRenderTargets);
                    }
                }
                Tools.EndPerformanceCounter("Custom render targets", this.customRenderTargets.length > 0);

                this._renderId++;
            }

            // Restore back buffer
            if (this.customRenderTargets.length > 0) {
                engine.restoreDefaultFramebuffer();
            }

            this._renderTargetsDuration.endMonitoring();
            this.activeCamera = currentActiveCamera;

            // Procedural textures
            if (this.proceduralTexturesEnabled) {
                Tools.StartPerformanceCounter("Procedural textures", this._proceduralTextures.length > 0);
                for (var proceduralIndex = 0; proceduralIndex < this._proceduralTextures.length; proceduralIndex++) {
                    var proceduralTexture = this._proceduralTextures[proceduralIndex];
                    if (proceduralTexture._shouldRender()) {
                        proceduralTexture.render();
                    }
                }
                Tools.EndPerformanceCounter("Procedural textures", this._proceduralTextures.length > 0);
            }

            // Clear
            if (this.autoClearDepthAndStencil || this.autoClear) {
                this._engine.clear(this.clearColor, this.autoClear || this.forceWireframe || this.forcePointsCloud, this.autoClearDepthAndStencil, this.autoClearDepthAndStencil);
            }

            // Shadows
            if (this.shadowsEnabled) {
                for (var lightIndex = 0; lightIndex < this.lights.length; lightIndex++) {
                    var light = this.lights[lightIndex];
                    var shadowGenerator = light.getShadowGenerator();

                    if (light.isEnabled() && light.shadowEnabled && shadowGenerator) {
                        var shadowMap = shadowGenerator.getShadowMap();
                        if (shadowMap.getScene().textures.indexOf(shadowMap) !== -1) {
                            this._renderTargets.push(shadowMap);
                        }
                    }
                }
            }

            // Depth renderer
            if (this._depthRenderer) {
                this._renderTargets.push(this._depthRenderer.getDepthMap());
            }

            // Geometry renderer
            if (this._geometryBufferRenderer) {
                this._renderTargets.push(this._geometryBufferRenderer.getGBuffer());
            }

            // RenderPipeline
            if (this._postProcessRenderPipelineManager) {
                this._postProcessRenderPipelineManager.update();
            }

            // Multi-cameras?
            if (this.activeCameras.length > 0) {
                for (var cameraIndex = 0; cameraIndex < this.activeCameras.length; cameraIndex++) {
                    if (cameraIndex > 0) {
                        this._engine.clear(null, false, true, true);
                    }

                    this._processSubCameras(this.activeCameras[cameraIndex]);
                }
            } else {
                if (!this.activeCamera) {
                    throw new Error("No camera defined");
                }

                this._processSubCameras(this.activeCamera);
            }

            // Intersection checks
            this._checkIntersections();

            // Update the audio listener attached to the camera
            if (AudioEngine) {
                this._updateAudioParameters();
            }

            // After render
            if (this.afterRender) {
                this.afterRender();
            }

            this.onAfterRenderObservable.notifyObservers(this);

            // Cleaning
            for (var index = 0; index < this._toBeDisposed.length; index++) {
                this._toBeDisposed.data[index].dispose();
                this._toBeDisposed[index] = null;
            }

            this._toBeDisposed.reset();

            if (this.dumpNextRenderTargets) {
                this.dumpNextRenderTargets = false;
            }

            Tools.EndPerformanceCounter("Scene rendering");
            this._lastFrameDuration.endMonitoring();
            this._totalMeshesCounter.addCount(this.meshes.length, true);
            this._totalLightsCounter.addCount(this.lights.length, true);
            this._totalMaterialsCounter.addCount(this.materials.length, true);
            this._totalTexturesCounter.addCount(this.textures.length, true);
            this._activeBones.addCount(0, true);
            this._activeIndices.addCount(0, true);
            this._activeParticles.addCount(0, true);
        }

        private _updateAudioParameters() {
            if (!this.audioEnabled || (this.mainSoundTrack.soundCollection.length === 0 && this.soundTracks.length === 1)) {
                return;
            }

            var listeningCamera: Camera;
            var audioEngine = Engine.audioEngine;

            if (this.activeCameras.length > 0) {
                listeningCamera = this.activeCameras[0];
            } else {
                listeningCamera = this.activeCamera;
            }

            if (listeningCamera && audioEngine.canUseWebAudio) {
                audioEngine.audioContext.listener.setPosition(listeningCamera.position.x, listeningCamera.position.y, listeningCamera.position.z);
                // for VR cameras
                if (listeningCamera.rigCameras && listeningCamera.rigCameras.length > 0) {
                    listeningCamera = listeningCamera.rigCameras[0];
                }
                var mat = Matrix.Invert(listeningCamera.getViewMatrix());
                var cameraDirection = Vector3.TransformNormal(new Vector3(0, 0, -1), mat);
                cameraDirection.normalize();
                audioEngine.audioContext.listener.setOrientation(cameraDirection.x, cameraDirection.y, cameraDirection.z, 0, 1, 0);
                var i: number;
                for (i = 0; i < this.mainSoundTrack.soundCollection.length; i++) {
                    var sound = this.mainSoundTrack.soundCollection[i];
                    if (sound.useCustomAttenuation) {
                        sound.updateDistanceFromListener();
                    }
                }
                for (i = 0; i < this.soundTracks.length; i++) {
                    for (var j = 0; j < this.soundTracks[i].soundCollection.length; j++) {
                        sound = this.soundTracks[i].soundCollection[j];
                        if (sound.useCustomAttenuation) {
                            sound.updateDistanceFromListener();
                        }
                    }
                }
            }
        }

        // Audio
        public get audioEnabled(): boolean {
            return this._audioEnabled;
        }

        public set audioEnabled(value: boolean) {
            this._audioEnabled = value;
            if (AudioEngine) {
                if (this._audioEnabled) {
                    this._enableAudio();
                }
                else {
                    this._disableAudio();
                }
            }
        }

        private _disableAudio() {
            var i: number;
            for (i = 0; i < this.mainSoundTrack.soundCollection.length; i++) {
                this.mainSoundTrack.soundCollection[i].pause();
            }
            for (i = 0; i < this.soundTracks.length; i++) {
                for (var j = 0; j < this.soundTracks[i].soundCollection.length; j++) {
                    this.soundTracks[i].soundCollection[j].pause();
                }
            }
        }

        private _enableAudio() {
            var i: number;
            for (i = 0; i < this.mainSoundTrack.soundCollection.length; i++) {
                if (this.mainSoundTrack.soundCollection[i].isPaused) {
                    this.mainSoundTrack.soundCollection[i].play();
                }
            }
            for (i = 0; i < this.soundTracks.length; i++) {
                for (var j = 0; j < this.soundTracks[i].soundCollection.length; j++) {
                    if (this.soundTracks[i].soundCollection[j].isPaused) {
                        this.soundTracks[i].soundCollection[j].play();
                    }
                }
            }
        }

        public get headphone(): boolean {
            return this._headphone;
        }

        public set headphone(value: boolean) {
            this._headphone = value;
            if (AudioEngine) {
                if (this._headphone) {
                    this._switchAudioModeForHeadphones();
                }
                else {
                    this._switchAudioModeForNormalSpeakers();
                }
            }
        }

        private _switchAudioModeForHeadphones() {
            this.mainSoundTrack.switchPanningModelToHRTF();

            for (var i = 0; i < this.soundTracks.length; i++) {
                this.soundTracks[i].switchPanningModelToHRTF();
            }
        }

        private _switchAudioModeForNormalSpeakers() {
            this.mainSoundTrack.switchPanningModelToEqualPower();

            for (var i = 0; i < this.soundTracks.length; i++) {
                this.soundTracks[i].switchPanningModelToEqualPower();
            }
        }

        public enableDepthRenderer(): DepthRenderer {
            if (this._depthRenderer) {
                return this._depthRenderer;
            }

            this._depthRenderer = new DepthRenderer(this);

            return this._depthRenderer;
        }

        public disableDepthRenderer(): void {
            if (!this._depthRenderer) {
                return;
            }

            this._depthRenderer.dispose();
            this._depthRenderer = null;
        }

        public enableGeometryBufferRenderer(ratio: number = 1): GeometryBufferRenderer {
            if (this._geometryBufferRenderer) {
                return this._geometryBufferRenderer;
            }

            this._geometryBufferRenderer = new GeometryBufferRenderer(this, ratio);
            if (!this._geometryBufferRenderer.isSupported) {
                this._geometryBufferRenderer = null;
            }

            return this._geometryBufferRenderer;
        }

        public disableGeometryBufferRenderer(): void {
            if (!this._geometryBufferRenderer) {
                return;
            }

            this._geometryBufferRenderer.dispose();
            this._geometryBufferRenderer = null;
        }

        public freezeMaterials(): void {
            for (var i = 0; i < this.materials.length; i++) {
                this.materials[i].freeze();
            }
        }

        public unfreezeMaterials(): void {
            for (var i = 0; i < this.materials.length; i++) {
                this.materials[i].unfreeze();
            }
        }

        public dispose(): void {
            this.beforeRender = null;
            this.afterRender = null;

            this.skeletons = [];
            this.morphTargetManagers = [];

            this.importedMeshesFiles = new Array<string>();

            if (this._depthRenderer) {
                this._depthRenderer.dispose();
            }

            // Smart arrays            
            if (this.activeCamera) {
                this.activeCamera._activeMeshes.dispose();
                this.activeCamera = null;
            }
            this._activeMeshes.dispose();
            this._renderingManager.dispose();
            this._processedMaterials.dispose();
            this._activeParticleSystems.dispose();
            this._activeSkeletons.dispose();
            this._softwareSkinnedMeshes.dispose();
            if (this._boundingBoxRenderer) {
                this._boundingBoxRenderer.dispose();
            }
            this._meshesForIntersections.dispose();
            this._toBeDisposed.dispose();

            // Debug layer
            if (this._debugLayer) {
                this._debugLayer.hide();
            }

            // Events
            this.onDisposeObservable.notifyObservers(this);

            this.onDisposeObservable.clear();
            this.onBeforeRenderObservable.clear();
            this.onAfterRenderObservable.clear();

            this.detachControl();

            // Release sounds & sounds tracks
            if (AudioEngine) {
                this.disposeSounds();
            }

            // Detach cameras
            var canvas = this._engine.getRenderingCanvas();
            var index;
            for (index = 0; index < this.cameras.length; index++) {
                this.cameras[index].detachControl(canvas);
            }

            // Release lights
            while (this.lights.length) {
                this.lights[0].dispose();
            }

            // Release meshes
            while (this.meshes.length) {
                this.meshes[0].dispose(true);
            }

            // Release cameras
            while (this.cameras.length) {
                this.cameras[0].dispose();
            }

            // Release materials
            while (this.materials.length) {
                this.materials[0].dispose();
            }

            // Release particles
            while (this.particleSystems.length) {
                this.particleSystems[0].dispose();
            }

            // Release sprites
            while (this.spriteManagers.length) {
                this.spriteManagers[0].dispose();
            }

            // Release layers
            while (this.layers.length) {
                this.layers[0].dispose();
            }
            while (this.highlightLayers.length) {
                this.highlightLayers[0].dispose();
            }

            // Release textures
            while (this.textures.length) {
                this.textures[0].dispose();
            }

            // Release UBO
            this._sceneUbo.dispose();

            // Post-processes
            this.postProcessManager.dispose();

            // Physics
            if (this._physicsEngine) {
                this.disablePhysicsEngine();
            }

            // Remove from engine
            index = this._engine.scenes.indexOf(this);

            if (index > -1) {
                this._engine.scenes.splice(index, 1);
            }

            this._engine.wipeCaches();
            this._engine = null;
        }

        public get isDisposed(): boolean {
            return !this._engine;
        }

        // Release sounds & sounds tracks
        public disposeSounds() {
            this.mainSoundTrack.dispose();

            for (var scIndex = 0; scIndex < this.soundTracks.length; scIndex++) {
                this.soundTracks[scIndex].dispose();
            }
        }

        // Octrees
        public getWorldExtends(): { min: Vector3; max: Vector3 } {
            var min = new Vector3(Number.MAX_VALUE, Number.MAX_VALUE, Number.MAX_VALUE);
            var max = new Vector3(-Number.MAX_VALUE, -Number.MAX_VALUE, -Number.MAX_VALUE);
            for (var index = 0; index < this.meshes.length; index++) {
                var mesh = this.meshes[index];

                mesh.computeWorldMatrix(true);
                var minBox = mesh.getBoundingInfo().boundingBox.minimumWorld;
                var maxBox = mesh.getBoundingInfo().boundingBox.maximumWorld;

                Tools.CheckExtends(minBox, min, max);
                Tools.CheckExtends(maxBox, min, max);
            }

            return {
                min: min,
                max: max
            };
        }

        public createOrUpdateSelectionOctree(maxCapacity = 64, maxDepth = 2): Octree<AbstractMesh> {
            if (!this._selectionOctree) {
                this._selectionOctree = new Octree<AbstractMesh>(Octree.CreationFuncForMeshes, maxCapacity, maxDepth);
            }

            var worldExtends = this.getWorldExtends();

            // Update octree
            this._selectionOctree.update(worldExtends.min, worldExtends.max, this.meshes);

            return this._selectionOctree;
        }

        // Picking
        public createPickingRay(x: number, y: number, world: Matrix, camera: Camera, cameraViewSpace = false): Ray {
            var engine = this._engine;

            if (!camera) {
                if (!this.activeCamera)
                    throw new Error("Active camera not set");

                camera = this.activeCamera;
            }

            var cameraViewport = camera.viewport;
            var viewport = cameraViewport.toGlobal(engine.getRenderWidth(), engine.getRenderHeight());

            // Moving coordinates to local viewport world
            x = x / this._engine.getHardwareScalingLevel() - viewport.x;
            y = y / this._engine.getHardwareScalingLevel() - (this._engine.getRenderHeight() - viewport.y - viewport.height);
            return Ray.CreateNew(x, y, viewport.width, viewport.height, world ? world : Matrix.Identity(), cameraViewSpace ? Matrix.Identity() : camera.getViewMatrix(), camera.getProjectionMatrix());
            //       return BABYLON.Ray.CreateNew(x / window.devicePixelRatio, y / window.devicePixelRatio, viewport.width, viewport.height, world ? world : BABYLON.Matrix.Identity(), camera.getViewMatrix(), camera.getProjectionMatrix());
        }

        public createPickingRayInCameraSpace(x: number, y: number, camera: Camera): Ray {
            if (!BABYLON.PickingInfo) {
                return null;
            }

            var engine = this._engine;

            if (!camera) {
                if (!this.activeCamera)
                    throw new Error("Active camera not set");

                camera = this.activeCamera;
            }

            var cameraViewport = camera.viewport;
            var viewport = cameraViewport.toGlobal(engine.getRenderWidth(), engine.getRenderHeight());
            var identity = Matrix.Identity();

            // Moving coordinates to local viewport world
            x = x / this._engine.getHardwareScalingLevel() - viewport.x;
            y = y / this._engine.getHardwareScalingLevel() - (this._engine.getRenderHeight() - viewport.y - viewport.height);
            return Ray.CreateNew(x, y, viewport.width, viewport.height, identity, identity, camera.getProjectionMatrix());
        }

        private _internalPick(rayFunction: (world: Matrix) => Ray, predicate: (mesh: AbstractMesh) => boolean, fastCheck?: boolean): PickingInfo {
            if (!BABYLON.PickingInfo) {
                return null;
            }

            var pickingInfo = null;

            for (var meshIndex = 0; meshIndex < this.meshes.length; meshIndex++) {
                var mesh = this.meshes[meshIndex];

                if (predicate) {
                    if (!predicate(mesh)) {
                        continue;
                    }
                } else if (!mesh.isEnabled() || !mesh.isVisible || !mesh.isPickable) {
                    continue;
                }

                var world = mesh.getWorldMatrix();
                var ray = rayFunction(world);

                var result = mesh.intersects(ray, fastCheck);
                if (!result || !result.hit)
                    continue;

                if (!fastCheck && pickingInfo != null && result.distance >= pickingInfo.distance)
                    continue;

                pickingInfo = result;

                if (fastCheck) {
                    break;
                }
            }

            return pickingInfo || new PickingInfo();
        }

        private _internalMultiPick(rayFunction: (world: Matrix) => Ray, predicate: (mesh: AbstractMesh) => boolean): PickingInfo[] {
            if (!BABYLON.PickingInfo) {
                return null;
            }            
            var pickingInfos = new Array<PickingInfo>();

            for (var meshIndex = 0; meshIndex < this.meshes.length; meshIndex++) {
                var mesh = this.meshes[meshIndex];

                if (predicate) {
                    if (!predicate(mesh)) {
                        continue;
                    }
                } else if (!mesh.isEnabled() || !mesh.isVisible || !mesh.isPickable) {
                    continue;
                }

                var world = mesh.getWorldMatrix();
                var ray = rayFunction(world);

                var result = mesh.intersects(ray, false);
                if (!result || !result.hit)
                    continue;

                pickingInfos.push(result);
            }

            return pickingInfos;
        }


        private _internalPickSprites(ray: Ray, predicate?: (sprite: Sprite) => boolean, fastCheck?: boolean, camera?: Camera): PickingInfo {
            if (!BABYLON.PickingInfo) {
                return null;
            }

            var pickingInfo = null;

            camera = camera || this.activeCamera;

            if (this.spriteManagers.length > 0) {
                for (var spriteIndex = 0; spriteIndex < this.spriteManagers.length; spriteIndex++) {
                    var spriteManager = this.spriteManagers[spriteIndex];

                    if (!spriteManager.isPickable) {
                        continue;
                    }

                    var result = spriteManager.intersects(ray, camera, predicate, fastCheck);
                    if (!result || !result.hit)
                        continue;

                    if (!fastCheck && pickingInfo != null && result.distance >= pickingInfo.distance)
                        continue;

                    pickingInfo = result;

                    if (fastCheck) {
                        break;
                    }
                }
            }

            return pickingInfo || new PickingInfo();
        }

        /// <summary>Launch a ray to try to pick a mesh in the scene</summary>
        /// <param name="x">X position on screen</param>
        /// <param name="y">Y position on screen</param>
        /// <param name="predicate">Predicate function used to determine eligible meshes. Can be set to null. In this case, a mesh must be enabled, visible and with isPickable set to true</param>
        /// <param name="fastCheck">Launch a fast check only using the bounding boxes. Can be set to null.</param>
        /// <param name="camera">camera to use for computing the picking ray. Can be set to null. In this case, the scene.activeCamera will be used</param>
        public pick(x: number, y: number, predicate?: (mesh: AbstractMesh) => boolean, fastCheck?: boolean, camera?: Camera): PickingInfo {
            return this._internalPick(world => this.createPickingRay(x, y, world, camera), predicate, fastCheck);
        }

        /// <summary>Launch a ray to try to pick a mesh in the scene</summary>
        /// <param name="x">X position on screen</param>
        /// <param name="y">Y position on screen</param>
        /// <param name="predicate">Predicate function used to determine eligible sprites. Can be set to null. In this case, a sprite must have isPickable set to true</param>
        /// <param name="fastCheck">Launch a fast check only using the bounding boxes. Can be set to null.</param>
        /// <param name="camera">camera to use for computing the picking ray. Can be set to null. In this case, the scene.activeCamera will be used</param>
        public pickSprite(x: number, y: number, predicate?: (sprite: Sprite) => boolean, fastCheck?: boolean, camera?: Camera): PickingInfo {
            return this._internalPickSprites(this.createPickingRayInCameraSpace(x, y, camera), predicate, fastCheck, camera);
        }

        public pickWithRay(ray: Ray, predicate: (mesh: Mesh) => boolean, fastCheck?: boolean): PickingInfo {
            return this._internalPick(world => {
                if (!this._pickWithRayInverseMatrix) {
                    this._pickWithRayInverseMatrix = Matrix.Identity();
                }
                world.invertToRef(this._pickWithRayInverseMatrix);
                return Ray.Transform(ray, this._pickWithRayInverseMatrix);
            }, predicate, fastCheck);
        }

        /// <summary>Launch a ray to try to pick a mesh in the scene</summary>
        /// <param name="x">X position on screen</param>
        /// <param name="y">Y position on screen</param>
        /// <param name="predicate">Predicate function used to determine eligible meshes. Can be set to null. In this case, a mesh must be enabled, visible and with isPickable set to true</param>
        /// <param name="camera">camera to use for computing the picking ray. Can be set to null. In this case, the scene.activeCamera will be used</param>
        public multiPick(x: number, y: number, predicate?: (mesh: AbstractMesh) => boolean, camera?: Camera): PickingInfo[] {
            return this._internalMultiPick(world => this.createPickingRay(x, y, world, camera), predicate);
        }

        /// <summary>Launch a ray to try to pick a mesh in the scene</summary>
        /// <param name="ray">Ray to use</param>
        /// <param name="predicate">Predicate function used to determine eligible meshes. Can be set to null. In this case, a mesh must be enabled, visible and with isPickable set to true</param>
        public multiPickWithRay(ray: Ray, predicate: (mesh: Mesh) => boolean): PickingInfo[] {
            return this._internalMultiPick(world => {
                if (!this._pickWithRayInverseMatrix) {
                    this._pickWithRayInverseMatrix = Matrix.Identity();
                }
                world.invertToRef(this._pickWithRayInverseMatrix);
                return Ray.Transform(ray, this._pickWithRayInverseMatrix);
            }, predicate);
        }

        public setPointerOverMesh(mesh: AbstractMesh): void {
            if (this._pointerOverMesh === mesh) {
                return;
            }

            if (this._pointerOverMesh && this._pointerOverMesh.actionManager) {
                this._pointerOverMesh.actionManager.processTrigger(ActionManager.OnPointerOutTrigger, ActionEvent.CreateNew(this._pointerOverMesh));
            }

            this._pointerOverMesh = mesh;
            if (this._pointerOverMesh && this._pointerOverMesh.actionManager) {
                this._pointerOverMesh.actionManager.processTrigger(ActionManager.OnPointerOverTrigger, ActionEvent.CreateNew(this._pointerOverMesh));
            }
        }

        public getPointerOverMesh(): AbstractMesh {
            return this._pointerOverMesh;
        }

        public setPointerOverSprite(sprite: Sprite): void {
            if (this._pointerOverSprite === sprite) {
                return;
            }

            if (this._pointerOverSprite && this._pointerOverSprite.actionManager) {
                this._pointerOverSprite.actionManager.processTrigger(ActionManager.OnPointerOutTrigger, ActionEvent.CreateNewFromSprite(this._pointerOverSprite, this));
            }

            this._pointerOverSprite = sprite;
            if (this._pointerOverSprite && this._pointerOverSprite.actionManager) {
                this._pointerOverSprite.actionManager.processTrigger(ActionManager.OnPointerOverTrigger, ActionEvent.CreateNewFromSprite(this._pointerOverSprite, this));
            }
        }

        public getPointerOverSprite(): Sprite {
            return this._pointerOverSprite;
        }

        // Physics
        public getPhysicsEngine(): PhysicsEngine {
            return this._physicsEngine;
        }

        /**
         * Enables physics to the current scene
         * @param {BABYLON.Vector3} [gravity] - the scene's gravity for the physics engine
         * @param {BABYLON.IPhysicsEnginePlugin} [plugin] - The physics engine to be used. defaults to OimoJS.
         * @return {boolean} was the physics engine initialized
         */
        public enablePhysics(gravity?: Vector3, plugin?: IPhysicsEnginePlugin): boolean {
            if (this._physicsEngine) {
                return true;
            }

            try {
                this._physicsEngine = new PhysicsEngine(gravity, plugin);
                return true;
            } catch (e) {
                Tools.Error(e.message);
                return false;
            }

        }

        public disablePhysicsEngine(): void {
            if (!this._physicsEngine) {
                return;
            }

            this._physicsEngine.dispose();
            this._physicsEngine = undefined;
        }

        public isPhysicsEnabled(): boolean {
            return this._physicsEngine !== undefined;
        }

        public deleteCompoundImpostor(compound: any): void {
            var mesh: AbstractMesh = compound.parts[0].mesh;
            mesh.physicsImpostor.dispose(/*true*/);
            mesh.physicsImpostor = null;
        }

        // Misc.
        public createDefaultCameraOrLight(createArcRotateCamera = false, replace = false, attachCameraControls = false) {
            // Dispose existing camera or light in replace mode.
            if (replace) {
                if (this.activeCamera) {
                    this.activeCamera.dispose();
                    this.activeCamera = null;
                }

                if (this.lights) {
                    for (var i = 0; i < this.lights.length; i++) {
                        this.lights[i].dispose();
                    }
                }
            }

            // Light
            if (this.lights.length === 0) {
                new HemisphericLight("default light", Vector3.Up(), this);
            }

            // Camera
            if (!this.activeCamera) {
                var worldExtends = this.getWorldExtends();
                var worldSize = worldExtends.max.subtract(worldExtends.min);
                var worldCenter = worldExtends.min.add(worldSize.scale(0.5));

                var camera: TargetCamera;
                var radius = worldSize.length() * 1.5;
                if (createArcRotateCamera) {
                    var arcRotateCamera = new ArcRotateCamera("default camera", 4.712, 1.571, radius, worldCenter, this);
                    arcRotateCamera.lowerRadiusLimit = radius * 0.01;
                    arcRotateCamera.wheelPrecision = 100 / radius;
                    camera = arcRotateCamera;
                }
                else {
                    var freeCamera = new FreeCamera("default camera", new Vector3(worldCenter.x, worldCenter.y, this.useRightHandedSystem ? -radius : radius), this);
                    freeCamera.setTarget(worldCenter);
                    camera = freeCamera;
                }
                camera.minZ = radius * 0.01;
                camera.maxZ = radius * 100;
                camera.speed = radius * 0.2;
                this.activeCamera = camera;

                if (attachCameraControls) {
                    camera.attachControl(this.getEngine().getRenderingCanvas());
                }
            }
        }

        public createDefaultSkybox(environmentTexture?: BaseTexture, pbr = false, scale = 1000, blur = 0): Mesh {
            if (environmentTexture) {
                this.environmentTexture = environmentTexture;
            }

            if (!this.environmentTexture) {
                Tools.Warn("Can not create default skybox without environment texture.");
                return;
            }

            // Skybox
            var hdrSkybox = BABYLON.Mesh.CreateBox("hdrSkyBox", scale, this);
            if (pbr) {
                let hdrSkyboxMaterial = new BABYLON.PBRMaterial("skyBox", this);
                hdrSkyboxMaterial.backFaceCulling = false;
                hdrSkyboxMaterial.reflectionTexture = environmentTexture.clone();
                hdrSkyboxMaterial.reflectionTexture.coordinatesMode = BABYLON.Texture.SKYBOX_MODE;
                hdrSkyboxMaterial.microSurface = 1.0 - blur;
                hdrSkyboxMaterial.disableLighting = true;
                hdrSkyboxMaterial.twoSidedLighting = true;
                hdrSkybox.infiniteDistance = true;
                hdrSkybox.material = hdrSkyboxMaterial;
            }
            else {
                let skyboxMaterial = new BABYLON.StandardMaterial("skyBox", this);
                skyboxMaterial.backFaceCulling = false;
                skyboxMaterial.reflectionTexture = environmentTexture.clone();
                skyboxMaterial.reflectionTexture.coordinatesMode = BABYLON.Texture.SKYBOX_MODE;
                skyboxMaterial.disableLighting = true;
                hdrSkybox.infiniteDistance = true;
                hdrSkybox.material = skyboxMaterial;
            }

            return hdrSkybox;
        }

        // Tags
        private _getByTags(list: any[], tagsQuery: string, forEach?: (item: any) => void): any[] {
            if (tagsQuery === undefined) {
                // returns the complete list (could be done with BABYLON.Tags.MatchesQuery but no need to have a for-loop here)
                return list;
            }

            var listByTags = [];

            forEach = forEach || ((item: any) => { return; });

            for (var i in list) {
                var item = list[i];
                if (Tags.MatchesQuery(item, tagsQuery)) {
                    listByTags.push(item);
                    forEach(item);
                }
            }

            return listByTags;
        }

        public getMeshesByTags(tagsQuery: string, forEach?: (mesh: AbstractMesh) => void): Mesh[] {
            return this._getByTags(this.meshes, tagsQuery, forEach);
        }

        public getCamerasByTags(tagsQuery: string, forEach?: (camera: Camera) => void): Camera[] {
            return this._getByTags(this.cameras, tagsQuery, forEach);
        }

        public getLightsByTags(tagsQuery: string, forEach?: (light: Light) => void): Light[] {
            return this._getByTags(this.lights, tagsQuery, forEach);
        }

        public getMaterialByTags(tagsQuery: string, forEach?: (material: Material) => void): Material[] {
            return this._getByTags(this.materials, tagsQuery, forEach).concat(this._getByTags(this.multiMaterials, tagsQuery, forEach));
        }

        /**
         * Overrides the default sort function applied in the renderging group to prepare the meshes.
         * This allowed control for front to back rendering or reversly depending of the special needs.
         * 
         * @param renderingGroupId The rendering group id corresponding to its index
         * @param opaqueSortCompareFn The opaque queue comparison function use to sort.
         * @param alphaTestSortCompareFn The alpha test queue comparison function use to sort.
         * @param transparentSortCompareFn The transparent queue comparison function use to sort.
         */
        public setRenderingOrder(renderingGroupId: number,
            opaqueSortCompareFn: (a: SubMesh, b: SubMesh) => number = null,
            alphaTestSortCompareFn: (a: SubMesh, b: SubMesh) => number = null,
            transparentSortCompareFn: (a: SubMesh, b: SubMesh) => number = null): void {

            this._renderingManager.setRenderingOrder(renderingGroupId,
                opaqueSortCompareFn,
                alphaTestSortCompareFn,
                transparentSortCompareFn);
        }

        /**
         * Specifies whether or not the stencil and depth buffer are cleared between two rendering groups.
         * 
         * @param renderingGroupId The rendering group id corresponding to its index
         * @param autoClearDepthStencil Automatically clears depth and stencil between groups if true.
         * @param depth Automatically clears depth between groups if true and autoClear is true.
         * @param stencil Automatically clears stencil between groups if true and autoClear is true.
         */
        public setRenderingAutoClearDepthStencil(renderingGroupId: number, autoClearDepthStencil: boolean,
            depth = true,
            stencil = true): void {
            this._renderingManager.setRenderingAutoClearDepthStencil(renderingGroupId, autoClearDepthStencil, depth, stencil);
        }

        /**
         * Will flag all materials as dirty to trigger new shader compilation
         * @param predicate If not null, it will be used to specifiy if a material has to be marked as dirty
         */
        public markAllMaterialsAsDirty(flag: number, predicate?: (mat: Material) => boolean): void {
            for (var material of this.materials) {
                if (predicate && !predicate(material)) {
                    continue;
                }
                material.markAsDirty(flag);
            }
        }
    }
}