lighting output is color3 instead of color4

src/Materials/Node/Blocks/PBR/pbrMetallicRoughnessBlock.ts

@@ -38,7 +38,7 @@ const mapOutputToVariable: { [name: string] : [string, string] } = {
     "sheenInd":     ["sheenOut.finalSheenRadianceScaled",           "!defined(UNLIT) && defined(REFLECTION) && defined(SHEEN) && defined(ENVIRONMENTBRDF)"],
     "clearcoatInd": ["clearcoatOut.finalClearCoatRadianceScaled",   "!defined(UNLIT) && defined(REFLECTION) && defined(CLEARCOAT)"],
     "refraction":   ["subSurfaceOut.finalRefraction",               "!defined(UNLIT) && defined(SS_REFRACTION)"],
-    "lighting":     ["finalColor", ""],
+    "lighting":     ["finalColor.rgb", ""],
     "shadow":       ["shadow", ""],
     "alpha":        ["alpha", ""],
 };
@@ -100,7 +100,7 @@ export class PBRMetallicRoughnessBlock extends NodeMaterialBlock {
         this.registerOutput("sheenInd", NodeMaterialBlockConnectionPointTypes.Color3, NodeMaterialBlockTargets.Fragment);
         this.registerOutput("clearcoatInd", NodeMaterialBlockConnectionPointTypes.Color3, NodeMaterialBlockTargets.Fragment);
         this.registerOutput("refraction", NodeMaterialBlockConnectionPointTypes.Color3, NodeMaterialBlockTargets.Fragment);
-        this.registerOutput("lighting", NodeMaterialBlockConnectionPointTypes.Color4, NodeMaterialBlockTargets.Fragment);
+        this.registerOutput("lighting", NodeMaterialBlockConnectionPointTypes.Color3, NodeMaterialBlockTargets.Fragment);
         this.registerOutput("shadow", NodeMaterialBlockConnectionPointTypes.Float, NodeMaterialBlockTargets.Fragment);
         this.registerOutput("alpha", NodeMaterialBlockConnectionPointTypes.Float, NodeMaterialBlockTargets.Fragment);
     }