Babylon.js/src/PostProcess/blackAndWhitePostProcess.ts

import { PostProcess, PostProcessOptions } from "PostProcess";
import { Camera } from "Cameras";
import { Effect } from "Materials";

    /**
     * Post process used to render in black and white
     */
    export class BlackAndWhitePostProcess extends PostProcess {
        /**
         * Linear about to convert he result to black and white (default: 1)
         */
        public degree = 1;

        /**
         * Creates a black and white post process
         * @see https://doc.babylonjs.com/how_to/how_to_use_postprocesses#black-and-white
         * @param name The name of the effect.
         * @param options The required width/height ratio to downsize to before computing the render pass.
         * @param camera The camera to apply the render pass to.
         * @param samplingMode The sampling mode to be used when computing the pass. (default: 0)
         * @param engine The engine which the post process will be applied. (default: current engine)
         * @param reusable If the post process can be reused on the same frame. (default: false)
         */
        constructor(name: string, options: number | PostProcessOptions, camera: Camera, samplingMode?: number, engine?: Engine, reusable?: boolean) {
            super(name, "blackAndWhite", ["degree"], null, options, camera, samplingMode, engine, reusable);

            this.onApplyObservable.add((effect: Effect) => {
                effect.setFloat("degree", this.degree);
            });
        }
    }