Merge pull request #5034 from NVIDIA/optimize-uniform-updates-2

Refresh light uniforms only when needed

src/renderers/WebGLRenderer.js

@@ -4291,6 +4291,7 @@ THREE.WebGLRenderer = function ( parameters ) {
 
 		var refreshProgram = false;
 		var refreshMaterial = false;
+		var refreshLights = false;
 
 		var program = material.program,
 			p_uniforms = program.uniforms,
@@ -4303,12 +4304,15 @@ THREE.WebGLRenderer = function ( parameters ) {
 
 			refreshProgram = true;
 			refreshMaterial = true;
+			refreshLights = true;
 
 		}
 
 		if ( material.id !== _currentMaterialId ) {
 
+			if ( _currentMaterialId === -1 ) refreshLights = true;
 			_currentMaterialId = material.id;
+
 			refreshMaterial = true;
 
 		}
@@ -4414,12 +4418,17 @@ THREE.WebGLRenderer = function ( parameters ) {
 
 				if ( _lightsNeedUpdate ) {
 
-					setupLights( program, lights );
+					refreshLights = true;
+					setupLights( lights );
 					_lightsNeedUpdate = false;
-
 				}
 
-				refreshUniformsLights( m_uniforms, _lights );
+				if ( refreshLights ) {
+					refreshUniformsLights( m_uniforms, _lights );
+					markUniformsLightsNeedsUpdate( m_uniforms, true );
+				} else {
+					markUniformsLightsNeedsUpdate( m_uniforms, false );
+				}
 
 			}
 
@@ -4700,6 +4709,32 @@ THREE.WebGLRenderer = function ( parameters ) {
 
 	};
 
+	// If uniforms are marked as clean, they don't need to be loaded to the GPU.
+
+	function markUniformsLightsNeedsUpdate ( uniforms, boolean ) {
+
+		uniforms.ambientLightColor.needsUpdate = boolean;
+
+		uniforms.directionalLightColor.needsUpdate = boolean;
+		uniforms.directionalLightDirection.needsUpdate = boolean;
+
+		uniforms.pointLightColor.needsUpdate = boolean;
+		uniforms.pointLightPosition.needsUpdate = boolean;
+		uniforms.pointLightDistance.needsUpdate = 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.needsUpdate = boolean;
+		uniforms.hemisphereLightGroundColor.needsUpdate = boolean;
+		uniforms.hemisphereLightDirection.needsUpdate = boolean;
+
+	};
+
 	function refreshUniformsShadow ( uniforms, lights ) {
 
 		if ( uniforms.shadowMatrix ) {
@@ -4772,6 +4807,9 @@ THREE.WebGLRenderer = function ( parameters ) {
 
 			var uniform = uniforms[ j ][ 0 ];
 
+			// needsUpdate property is not added to all uniforms.
+			if ( uniform.needsUpdate === false ) continue;
+
 			var type = uniform.type;
 			var value = uniform.value;
 
@@ -5001,7 +5039,7 @@ THREE.WebGLRenderer = function ( parameters ) {
 
 	};
 
-	function setupLights ( program, lights ) {
+	function setupLights ( lights ) {
 
 		var l, ll, light, n,
 		r = 0, g = 0, b = 0,