WebGLPrograms: Enable uvs only in vertex shader.

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

 export default /* glsl */`
-#ifdef USE_UV
+#if ( defined( USE_UV ) && ! defined( UVS_VERTEX_ONLY ) )
 
 	varying vec2 vUv;
 

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

 export default /* glsl */`
 #ifdef USE_UV
 
-	varying vec2 vUv;
+	#ifdef UVS_VERTEX_ONLY
+
+		vec2 vUv;
+
+	#else
+
+		varying vec2 vUv;
+
+	#endif
+
 	uniform mat3 uvTransform;
 
 #endif

src/renderers/webgl/WebGLProgram.js

@@ -470,6 +470,7 @@ function WebGLProgram( renderer, extensions, code, material, shader, parameters
 			parameters.vertexTangents ? '#define USE_TANGENT' : '',
 			parameters.vertexColors ? '#define USE_COLOR' : '',
 			parameters.vertexUvs ? '#define USE_UV' : '',
+			parameters.uvsVertexOnly ? '#define UVS_VERTEX_ONLY' : '',
 
 			parameters.flatShading ? '#define FLAT_SHADED' : '',
 
@@ -595,6 +596,7 @@ function WebGLProgram( renderer, extensions, code, material, shader, parameters
 			parameters.vertexTangents ? '#define USE_TANGENT' : '',
 			parameters.vertexColors ? '#define USE_COLOR' : '',
 			parameters.vertexUvs ? '#define USE_UV' : '',
+			parameters.uvsVertexOnly ? '#define UVS_VERTEX_ONLY' : '',
 
 			parameters.gradientMap ? '#define USE_GRADIENTMAP' : '',
 

src/renderers/webgl/WebGLPrograms.js

@@ -39,7 +39,7 @@ function WebGLPrograms( renderer, extensions, capabilities ) {
 		"map", "mapEncoding", "matcap", "matcapEncoding", "envMap", "envMapMode", "envMapEncoding", "envMapCubeUV",
 		"lightMap", "aoMap", "emissiveMap", "emissiveMapEncoding", "bumpMap", "normalMap", "objectSpaceNormalMap", "tangentSpaceNormalMap", "clearcoatNormalMap", "displacementMap", "specularMap",
 		"roughnessMap", "metalnessMap", "gradientMap",
-		"alphaMap", "combine", "vertexColors", "vertexTangents", "vertexUvs", "fog", "useFog", "fogExp2",
+		"alphaMap", "combine", "vertexColors", "vertexTangents", "vertexUvs", "uvsVertexOnly", "fog", "useFog", "fogExp2",
 		"flatShading", "sizeAttenuation", "logarithmicDepthBuffer", "skinning",
 		"maxBones", "useVertexTexture", "morphTargets", "morphNormals",
 		"maxMorphTargets", "maxMorphNormals", "premultipliedAlpha",
@@ -186,6 +186,7 @@ function WebGLPrograms( renderer, extensions, capabilities ) {
 			vertexTangents: ( material.normalMap && material.vertexTangents ),
 			vertexColors: material.vertexColors,
 			vertexUvs: !! material.map || !! material.bumpMap || !! material.normalMap || !! material.specularMap || !! material.alphaMap || !! material.emissiveMap || !! material.roughnessMap || !! material.metalnessMap || !! material.clearcoatNormalMap || !! material.displacementMap,
+			uvsVertexOnly: ! ( !! material.map || !! material.bumpMap || !! material.normalMap || !! material.specularMap || !! material.alphaMap || !! material.emissiveMap || !! material.roughnessMap || !! material.metalnessMap || !! material.clearcoatNormalMap ) && !! material.displacementMap,
 
 			fog: !! fog,
 			useFog: material.fog,