Babylon.js/src/Debug/boneAxesViewer.ts

import { Nullable } from "../types";
import { AxesViewer } from "../Debug/axesViewer";
import { Vector3, Axis } from "../Maths/math";
import { Mesh } from "../Meshes/mesh";
import { Bone } from "../Bones/bone";
import { Scene } from "../scene";

/**
     * The BoneAxesViewer will attach 3 axes to a specific bone of a specific mesh
     * @see demo here: https://www.babylonjs-playground.com/#0DE8F4#8
     */
    export class BoneAxesViewer extends AxesViewer {

        /**
         * Gets or sets the target mesh where to display the axes viewer
         */
        public mesh: Nullable<Mesh>;
        /**
         * Gets or sets the target bone where to display the axes viewer
         */
        public bone: Nullable<Bone>;

        /** Gets current position */
        public pos = Vector3.Zero();
        /** Gets direction of X axis */
        public xaxis = Vector3.Zero();
        /** Gets direction of Y axis */
        public yaxis = Vector3.Zero();
        /** Gets direction of Z axis */
        public zaxis = Vector3.Zero();

        /**
         * Creates a new BoneAxesViewer
         * @param scene defines the hosting scene
         * @param bone defines the target bone
         * @param mesh defines the target mesh
         * @param scaleLines defines a scaling factor for line length (1 by default)
         */
        constructor(scene: Scene, bone: Bone, mesh: Mesh, scaleLines = 1) {

            super(scene, scaleLines);

            this.mesh = mesh;
            this.bone = bone;

        }

        /**
         * Force the viewer to update
         */
        public update(): void {

            if (!this.mesh || !this.bone) {
                return;
            }

            var bone = this.bone;
            bone.getAbsolutePositionToRef(this.mesh, this.pos);
            bone.getDirectionToRef(Axis.X, this.mesh, this.xaxis);
            bone.getDirectionToRef(Axis.Y, this.mesh, this.yaxis);
            bone.getDirectionToRef(Axis.Z, this.mesh, this.zaxis);

            super.update(this.pos, this.xaxis, this.yaxis, this.zaxis);

        }

        /** Releases resources */
        public dispose() {

            if (this.mesh) {
                this.mesh = null;
                this.bone = null;

                super.dispose();

            }
        }

    }