WebGLShadowMap: Use converted BufferGeometry if possible.

src/renderers/webgl/WebGLShadowMap.js

@@ -277,9 +277,7 @@ function WebGLShadowMap( _renderer, _objects, maxTextureSize ) {
 
 	}
 
-	function getDepthMaterial( object, material, light, shadowCameraNear, shadowCameraFar, type ) {
-
-		var geometry = object.geometry;
+	function getDepthMaterial( object, geometry, material, light, shadowCameraNear, shadowCameraFar, type ) {
 
 		var result = null;
 
@@ -418,7 +416,7 @@ function WebGLShadowMap( _renderer, _objects, maxTextureSize ) {
 
 						if ( groupMaterial && groupMaterial.visible ) {
 
-							var depthMaterial = getDepthMaterial( object, groupMaterial, light, shadowCamera.near, shadowCamera.far, type );
+							var depthMaterial = getDepthMaterial( object, geometry, groupMaterial, light, shadowCamera.near, shadowCamera.far, type );
 
 							_renderer.renderBufferDirect( shadowCamera, null, geometry, depthMaterial, object, group );
 
@@ -428,7 +426,7 @@ function WebGLShadowMap( _renderer, _objects, maxTextureSize ) {
 
 				} else if ( material.visible ) {
 
-					var depthMaterial = getDepthMaterial( object, material, light, shadowCamera.near, shadowCamera.far, type );
+					var depthMaterial = getDepthMaterial( object, geometry, material, light, shadowCamera.near, shadowCamera.far, type );
 
 					_renderer.renderBufferDirect( shadowCamera, null, geometry, depthMaterial, object, null );