copy( source ) {

		this.lightsNode = source.lightsNode;
		this.envNode = source.envNode;

		this.colorNode = source.colorNode;
		this.normalNode = source.normalNode;
		this.opacityNode = source.opacityNode;
		this.backdropNode = source.backdropNode;
		this.backdropAlphaNode = source.backdropAlphaNode;
		this.alphaTestNode = source.alphaTestNode;
		this.maskNode = source.maskNode;

		this.positionNode = source.positionNode;
		this.geometryNode = source.geometryNode;

		this.depthNode = source.depthNode;
		this.receivedShadowPositionNode = source.receivedShadowPositionNode;
		this.castShadowPositionNode = source.castShadowPositionNode;
		this.receivedShadowNode = source.receivedShadowNode;
		this.castShadowNode = source.castShadowNode;

		this.outputNode = source.outputNode;
		this.mrtNode = source.mrtNode;

		this.fragmentNode = source.fragmentNode;
		this.vertexNode = source.vertexNode;

		return super.copy( source );

	}
Copies the properties of the given node material to this instance.

@param {NodeMaterial} source - The material to copy.
@return {NodeMaterial} A reference to this node material.