Babylon playground for simple custom ShaderMaterial

playground.js

var createScene = function() {
    var scene = new BABYLON.Scene(engine);

    var camera = new BABYLON.ArcRotateCamera("Camera", - Math.PI / 2, Math.PI / 4, 10, BABYLON.Vector3.Zero(), scene);

    camera.attachControl(canvas, true);

    BABYLON.Effect.ShadersStore["customVertexShader"]= `   
		precision highp float;
    	// Attributes
    	attribute vec3 position;
        attribute vec3 normal;
    	attribute vec2 uv;
    	// Uniforms
    	uniform mat4 worldViewProjection;
        uniform float time;
    	// Varying
    	varying vec2 vUV;
    	void main(void) {
            vec4 q = vec4(position, 1.0);
            vec3 p = q.xyz;
            p.x = p.x + sin(2.0 * position.y + time);
            p.y = p.y + sin(time + 4.0);
    	    gl_Position = worldViewProjection * vec4(p, 1.0);
    	    vUV = uv;
    	}`;

    BABYLON.Effect.ShadersStore["customFragmentShader"]=`
	    precision highp float;
        varying vec2 vUV;
    	uniform sampler2D textureSampler;
    	void main(void) {
            gl_FragColor = texture2D(textureSampler, vUV);
    	}`;

    var shaderMaterial = new BABYLON.ShaderMaterial("shader", scene, {
        vertex: "custom",
        fragment: "custom",
	    },
        {
			attributes: ["position", "normal", "uv"],
			uniforms: ["world", "worldView", "worldViewProjection", "view", "projection"]
        });

    var mainTexture = new BABYLON.Texture("textures/amiga.jpg", scene);

    shaderMaterial.setTexture("textureSampler", mainTexture);
    
    var box = BABYLON.MeshBuilder.CreateBox("box", {}, scene);

    box.material = shaderMaterial;            

    var time = 0.;
    scene.registerBeforeRender(function() {
        box.material.setFloat("time", time);
        time += 0.01;        
    });

	return scene;
}