Replace uniform.skipUpdate with uniform.needsUpdate

This is consistent with usage of needsUpdate throughout the rest of the
code. The property is not added to all uniforms for now, so the check
needs to be needsUpdate === false rather than just ! needsUpdate.

src/renderers/WebGLRenderer.js

@@ -4421,9 +4421,9 @@ THREE.WebGLRenderer = function ( parameters ) {
 
 				if ( refreshLights ) {
 					refreshUniformsLights( m_uniforms, _lights );
-					markUniformsLightsSkipUpdate( m_uniforms, false );
+					markUniformsLightsNeedsUpdate( m_uniforms, true );
 				} else {
-					markUniformsLightsSkipUpdate( m_uniforms, true );
+					markUniformsLightsNeedsUpdate( m_uniforms, false );
 				}
 
 			}
@@ -4707,27 +4707,27 @@ THREE.WebGLRenderer = function ( parameters ) {
 
 	// If uniforms are marked as clean, they don't need to be loaded to the GPU.
 
-	function markUniformsLightsSkipUpdate ( uniforms, boolean ) {
+	function markUniformsLightsNeedsUpdate ( uniforms, boolean ) {
 
-		uniforms.ambientLightColor.skipUpdate = boolean;
+		uniforms.ambientLightColor.needsUpdate = boolean;
 
-		uniforms.directionalLightColor.skipUpdate = boolean;
-		uniforms.directionalLightDirection.skipUpdate = boolean;
+		uniforms.directionalLightColor.needsUpdate = boolean;
+		uniforms.directionalLightDirection.needsUpdate = boolean;
 
-		uniforms.pointLightColor.skipUpdate = boolean;
-		uniforms.pointLightPosition.skipUpdate = boolean;
-		uniforms.pointLightDistance.skipUpdate = boolean;
+		uniforms.pointLightColor.needsUpdate = boolean;
+		uniforms.pointLightPosition.needsUpdate = boolean;
+		uniforms.pointLightDistance.needsUpdate = boolean;
 
-		uniforms.spotLightColor.skipUpdate = boolean;
-		uniforms.spotLightPosition.skipUpdate = boolean;
-		uniforms.spotLightDistance.skipUpdate = boolean;
-		uniforms.spotLightDirection.skipUpdate = boolean;
-		uniforms.spotLightAngleCos.skipUpdate = boolean;
-		uniforms.spotLightExponent.skipUpdate = boolean;
+		uniforms.spotLightColor.needsUpdate = boolean;
+		uniforms.spotLightPosition.needsUpdate = boolean;
+		uniforms.spotLightDistance.needsUpdate = boolean;
+		uniforms.spotLightDirection.needsUpdate = boolean;
+		uniforms.spotLightAngleCos.needsUpdate = boolean;
+		uniforms.spotLightExponent.needsUpdate = boolean;
 
-		uniforms.hemisphereLightSkyColor.skipUpdate = boolean;
-		uniforms.hemisphereLightGroundColor.skipUpdate = boolean;
-		uniforms.hemisphereLightDirection.skipUpdate = boolean;
+		uniforms.hemisphereLightSkyColor.needsUpdate = boolean;
+		uniforms.hemisphereLightGroundColor.needsUpdate = boolean;
+		uniforms.hemisphereLightDirection.needsUpdate = boolean;
 
 	};
 
@@ -4805,7 +4805,8 @@ THREE.WebGLRenderer = function ( parameters ) {
 
 			var uniform = uniforms[ j ][ 0 ];
 
-			if ( uniform.skipUpdate ) continue;
+			// needsUpdate property is not added to all uniforms.
+			if ( uniform.needsUpdate === false ) continue;
 
 			var type = uniform.type;
 			var value = uniform.value;