WebGLRenderer, GLTFLoader: Clean up .vertexTangents removal. (#22182)

examples/jsm/exporters/GLTFExporter.js

@@ -1219,14 +1219,10 @@ class GLTFWriter {
 
 			const normalMapDef = { index: this.processTexture( material.normalMap ) };
 
-			if ( material.normalScale && material.normalScale.x !== - 1 ) {
-
-				if ( material.normalScale.x !== material.normalScale.y ) {
-
-					console.warn( 'THREE.GLTFExporter: Normal scale components are different, ignoring Y and exporting X.' );
-
-				}
+			if ( material.normalScale && material.normalScale.x !== 1 ) {
 
+				// glTF normal scale is univariate. Ignore `y`, which may be flipped.
+				// Context: https://github.com/mrdoob/three.js/issues/11438#issuecomment-507003995
 				normalMapDef.scale = material.normalScale.x;
 
 			}

examples/jsm/loaders/GLTFLoader.js

@@ -684,7 +684,8 @@ class GLTFMaterialsClearcoatExtension {
 
 				const scale = extension.clearcoatNormalTexture.scale;
 
-				materialParams.clearcoatNormalScale = new Vector2( scale, scale );
+				// https://github.com/mrdoob/three.js/issues/11438#issuecomment-507003995
+				materialParams.clearcoatNormalScale = new Vector2( scale, - scale );
 
 			}
 
@@ -2891,6 +2892,14 @@ class GLTFParser {
 				if ( useVertexColors ) cachedMaterial.vertexColors = true;
 				if ( useFlatShading ) cachedMaterial.flatShading = true;
 
+				if ( useVertexTangents ) {
+
+					// https://github.com/mrdoob/three.js/issues/11438#issuecomment-507003995
+					if ( cachedMaterial.normalScale ) cachedMaterial.normalScale.y *= - 1;
+					if ( cachedMaterial.clearcoatNormalScale ) cachedMaterial.clearcoatNormalScale.y *= - 1;
+
+				}
+
 				this.cache.add( cacheKey, cachedMaterial );
 
 				this.associations.set( cachedMaterial, this.associations.get( material ) );
@@ -3029,9 +3038,12 @@ class GLTFParser {
 
 			pending.push( parser.assignTexture( materialParams, 'normalMap', materialDef.normalTexture ) );
 
+			// https://github.com/mrdoob/three.js/issues/11438#issuecomment-507003995
+			materialParams.normalScale = new Vector2( 1, - 1 );
+
 			if ( materialDef.normalTexture.scale !== undefined ) {
 
-				materialParams.normalScale = new Vector2( materialDef.normalTexture.scale, materialDef.normalTexture.scale );
+				materialParams.normalScale.set( materialDef.normalTexture.scale, - materialDef.normalTexture.scale );
 
 			}
 

src/renderers/shaders/ShaderChunk/clearcoat_normal_fragment_maps.glsl.js

@@ -4,12 +4,6 @@ export default /* glsl */`
 	vec3 clearcoatMapN = texture2D( clearcoatNormalMap, vUv ).xyz * 2.0 - 1.0;
 	clearcoatMapN.xy *= clearcoatNormalScale;
 
-	#ifdef FLIP_NORMAL_SCALE_Y
-
-		clearcoatMapN.y *= -1.0;
-
-	#endif
-
 	#ifdef USE_TANGENT
 
 		clearcoatNormal = normalize( vTBN * clearcoatMapN );

src/renderers/shaders/ShaderChunk/normal_fragment_maps.glsl.js

@@ -23,12 +23,6 @@ export default /* glsl */`
 	vec3 mapN = texture2D( normalMap, vUv ).xyz * 2.0 - 1.0;
 	mapN.xy *= normalScale;
 
-	#ifdef FLIP_NORMAL_SCALE_Y
-
-		mapN.y *= -1.0;
-
-	#endif
-
 	#ifdef USE_TANGENT
 
 		normal = normalize( vTBN * mapN );

src/renderers/webgl/WebGLProgram.js

@@ -477,7 +477,6 @@ function WebGLProgram( renderer, cacheKey, parameters, bindingStates ) {
 			parameters.vertexAlphas ? '#define USE_COLOR_ALPHA' : '',
 			parameters.vertexUvs ? '#define USE_UV' : '',
 			parameters.uvsVertexOnly ? '#define UVS_VERTEX_ONLY' : '',
-			parameters.flipNormalScaleY ? '#define FLIP_NORMAL_SCALE_Y' : '',
 
 			parameters.flatShading ? '#define FLAT_SHADED' : '',
 
@@ -621,7 +620,6 @@ function WebGLProgram( renderer, cacheKey, parameters, bindingStates ) {
 			parameters.vertexAlphas ? '#define USE_COLOR_ALPHA' : '',
 			parameters.vertexUvs ? '#define USE_UV' : '',
 			parameters.uvsVertexOnly ? '#define UVS_VERTEX_ONLY' : '',
-			parameters.flipNormalScaleY ? '#define FLIP_NORMAL_SCALE_Y' : '',
 
 			parameters.gradientMap ? '#define USE_GRADIENTMAP' : '',
 

src/renderers/webgl/WebGLPrograms.js

@@ -38,7 +38,7 @@ function WebGLPrograms( renderer, cubemaps, extensions, capabilities, bindingSta
 		'map', 'mapEncoding', 'matcap', 'matcapEncoding', 'envMap', 'envMapMode', 'envMapEncoding', 'envMapCubeUV',
 		'lightMap', 'lightMapEncoding', 'aoMap', 'emissiveMap', 'emissiveMapEncoding', 'bumpMap', 'normalMap', 'objectSpaceNormalMap', 'tangentSpaceNormalMap', 'clearcoatMap', 'clearcoatRoughnessMap', 'clearcoatNormalMap', 'displacementMap', 'specularMap',
 		'roughnessMap', 'metalnessMap', 'gradientMap',
-		'alphaMap', 'combine', 'vertexColors', 'vertexAlphas', 'vertexTangents', 'vertexUvs', 'uvsVertexOnly', 'flipNormalScaleY', 'fog', 'useFog', 'fogExp2',
+		'alphaMap', 'combine', 'vertexColors', 'vertexAlphas', 'vertexTangents', 'vertexUvs', 'uvsVertexOnly', 'fog', 'useFog', 'fogExp2',
 		'flatShading', 'sizeAttenuation', 'logarithmicDepthBuffer', 'skinning',
 		'maxBones', 'useVertexTexture', 'morphTargets', 'morphNormals', 'premultipliedAlpha',
 		'numDirLights', 'numPointLights', 'numSpotLights', 'numHemiLights', 'numRectAreaLights',
@@ -213,7 +213,6 @@ function WebGLPrograms( renderer, cubemaps, extensions, capabilities, bindingSta
 			vertexAlphas: material.vertexColors === true && object.geometry && object.geometry.attributes.color && object.geometry.attributes.color.itemSize === 4,
 			vertexUvs: !! material.map || !! material.bumpMap || !! material.normalMap || !! material.specularMap || !! material.alphaMap || !! material.emissiveMap || !! material.roughnessMap || !! material.metalnessMap || !! material.clearcoatMap || !! material.clearcoatRoughnessMap || !! material.clearcoatNormalMap || !! material.displacementMap || !! material.transmissionMap || !! material.thicknessMap,
 			uvsVertexOnly: ! ( !! material.map || !! material.bumpMap || !! material.normalMap || !! material.specularMap || !! material.alphaMap || !! material.emissiveMap || !! material.roughnessMap || !! material.metalnessMap || !! material.clearcoatNormalMap || !! material.transmission || !! material.transmissionMap || !! material.thicknessMap ) && !! material.displacementMap,
-			flipNormalScaleY: ( ( material.normalMap && material.normalMap.flipY === false || material.clearcoatNormalMap && material.clearcoatNormalMap.flipY === false ) && ! ( object.geometry && object.geometry.attributes.tangent ) ),
 
 			fog: !! fog,
 			useFog: material.fog,