Fixed UniformUtils .clone() breakage.

src/renderers/shaders/UniformsUtils.js

@@ -36,10 +36,10 @@ var UniformsUtils = {
 
 				var parameter_src = uniforms_src[ u ][ p ];
 
-				if ( parameter_src.isColor ||
+				if ( parameter_src && ( parameter_src.isColor ||
 					parameter_src.isMatrix3 || parameter_src.isMatrix4 ||
 					parameter_src.isVector2 || parameter_src.isVector3 || parameter_src.isVector4 ||
-					parameter_src.isTexture ) {
+					parameter_src.isTexture ) ) {
 
 					uniforms_dst[ u ][ p ] = parameter_src.clone();