Updated builds.

build/three.js

@@ -7472,6 +7472,7 @@ THREE.Object3D = function () {
 	this.receiveShadow = false;
 
 	this.frustumCulled = true;
+	this.renderOrder = 0;
 
 	this.userData = {};
 
@@ -20973,7 +20974,11 @@ THREE.WebGLRenderer = function ( parameters ) {
 
 	function painterSortStable ( a, b ) {
 
-		if ( a.material.id !== b.material.id ) {
+		if ( a.renderOrder !== b.renderOrder ) {
+
+			return a.renderOrder - b.renderOrder;
+
+		} else if ( a.material.id !== b.material.id ) {
 
 			return a.material.id - b.material.id;
 
@@ -20991,7 +20996,11 @@ THREE.WebGLRenderer = function ( parameters ) {
 
 	function reversePainterSortStable ( a, b ) {
 
-		if ( a.z !== b.z ) {
+		if ( a.renderOrder !== b.renderOrder ) {
+
+			return a.renderOrder - b.renderOrder;
+
+		} if ( a.z !== b.z ) {
 
 			return b.z - a.z;