WebGLRenderer: Set group to null to maintain renderItem object structure. @tschw sounds good?

src/renderers/WebGLRenderer.js

@@ -803,7 +803,7 @@ THREE.WebGLRenderer = function ( parameters ) {
 
 		}
 
-		if ( group === undefined ) {
+		if ( group === null ) {
 
 			var count;
 
@@ -1338,7 +1338,7 @@ THREE.WebGLRenderer = function ( parameters ) {
 
 					} else {
 
-						pushRenderItem( object, geometry, material, _vector3.z );
+						pushRenderItem( object, geometry, material, _vector3.z, null );
 
 					}
 

src/renderers/webgl/WebGLShadowMap.js

@@ -224,7 +224,7 @@ THREE.WebGLShadowMap = function ( _renderer, _lights, _objects ) {
 
 				} else {
 
-					_renderer.renderBufferDirect( shadowCamera, _lights, null, geometry, getDepthMaterial( object, material ), object );
+					_renderer.renderBufferDirect( shadowCamera, _lights, null, geometry, getDepthMaterial( object, material ), object, null );
 
 				}