ThreeJS Material Clone and inheritance

• The material object

Material.prototype = Object.assign(Object.create(EventDispatcher.prototype), {
	constructor: Material,

	clone: function () {
		return new this.constructor().copy(this);
	},

	copy: function (source) {
		this.name = source.name;

		this.fog = source.fog;

		this.blending = source.blending;
		this.side = source.side;
		this.flatShading = source.flatShading;
		this.vertexColors = source.vertexColors;

		this.opacity = source.opacity;
		this.transparent = source.transparent;

		this.blendSrc = source.blendSrc;
		this.blendDst = source.blendDst;
		this.blendEquation = source.blendEquation;
		this.blendSrcAlpha = source.blendSrcAlpha;
		this.blendDstAlpha = source.blendDstAlpha;
		this.blendEquationAlpha = source.blendEquationAlpha;

		this.depthFunc = source.depthFunc;
		this.depthTest = source.depthTest;
		this.depthWrite = source.depthWrite;

		this.stencilWriteMask = source.stencilWriteMask;
		this.stencilFunc = source.stencilFunc;
		this.stencilRef = source.stencilRef;
		this.stencilFuncMask = source.stencilFuncMask;
		this.stencilFail = source.stencilFail;
		this.stencilZFail = source.stencilZFail;
		this.stencilZPass = source.stencilZPass;
		this.stencilWrite = source.stencilWrite;

		const srcPlanes = source.clippingPlanes;
		let dstPlanes = null;

		if(srcPlanes ! = =null) {
			const n = srcPlanes.length;
			dstPlanes = new Array(n);

			for (let i = 0; i !== n; ++i) {
				dstPlanes[i] = srcPlanes[i].clone();
			}
		}

		this.clippingPlanes = dstPlanes;
		this.clipIntersection = source.clipIntersection;
		this.clipShadows = source.clipShadows;

		this.shadowSide = source.shadowSide;

		this.colorWrite = source.colorWrite;

		this.precision = source.precision;

		this.polygonOffset = source.polygonOffset;
		this.polygonOffsetFactor = source.polygonOffsetFactor;
		this.polygonOffsetUnits = source.polygonOffsetUnits;

		this.dithering = source.dithering;

		this.alphaTest = source.alphaTest;
		this.premultipliedAlpha = source.premultipliedAlpha;

		this.visible = source.visible;

		this.toneMapped = source.toneMapped;

		this.userData = JSON.parse(JSON.stringify(source.userData));

		return this;
	},

	dispose: function () {
		this.dispatchEvent({ type: 'dispose'}); }});Object.defineProperty(Material.prototype, 'needsUpdate', {
	set: function (value) {
		if (value === true) this.version++; }});Copy the code

• PhysicalMaterial inherits the Material prototype and the material method;

function MeshPhysicalMaterial(parameters) {
	MeshStandardMaterial.call(this); . } MeshPhysicalMaterial.prototype.copy =function (source) {
	MeshStandardMaterial.prototype.copy.call(this, source); . }Copy the code