three.js/examples/js/nodes/inputs/Matrix4Node.js

/**
 * @author sunag / http://www.sunag.com.br/
 */

THREE.Matrix4Node = function ( matrix ) {

	THREE.InputNode.call( this, 'm4' );

	this.value = matrix || new THREE.Matrix4();

};

THREE.Matrix4Node.prototype = Object.create( THREE.InputNode.prototype );
THREE.Matrix4Node.prototype.constructor = THREE.Matrix4Node;
THREE.Matrix4Node.prototype.nodeType = "Matrix4";

THREE.Matrix4Node.prototype.toJSON = function ( meta ) {

	var data = this.getJSONNode( meta );

	if ( ! data ) {

		data = this.createJSONNode( meta );

		data.elements = this.value.elements.concat();

	}

	return data;

};