GLTFLoader: Clean up UV set messages

Almost all models that use occlusionTexture use texCoord 0 - the loader
prints a console message for each material for such models which seems
redundant / excessive.

However, if other textures use texCoord that's not 0, the resulting
texture will not be rendered properly. We now detect this case and issue
a warning.

examples/js/loaders/GLTFLoader.js

@@ -1971,6 +1971,14 @@ THREE.GLTFLoader = ( function () {
 
 			}
 
+			// Materials sample aoMap from UV set 1 and other maps from UV set 0 - this can't be configured
+			// However, we will copy UV set 0 to UV set 1 on demand for aoMap
+			if ( mapDef.texCoord !== undefined && mapDef.texCoord != 0 && ! ( mapName === 'aoMap' && mapDef.texCoord == 1 ) ) {
+
+				console.warn( 'THREE.GLTFLoader: Custom UV set ' + mapDef.texCoord + ' for texture ' + mapName + ' not yet supported.' );
+
+			}
+
 			if ( parser.extensions[ EXTENSIONS.KHR_TEXTURE_TRANSFORM ] ) {
 
 				var transform = mapDef.extensions !== undefined ? mapDef.extensions[ EXTENSIONS.KHR_TEXTURE_TRANSFORM ] : undefined;
@@ -2090,7 +2098,6 @@ THREE.GLTFLoader = ( function () {
 
 		if ( material.aoMap && geometry.attributes.uv2 === undefined && geometry.attributes.uv !== undefined ) {
 
-			console.log( 'THREE.GLTFLoader: Duplicating UVs to support aoMap.' );
 			geometry.setAttribute( 'uv2', new THREE.BufferAttribute( geometry.attributes.uv.array, 2 ) );
 
 		}

examples/jsm/loaders/GLTFLoader.js

@@ -2038,6 +2038,14 @@ var GLTFLoader = ( function () {
 
 			}
 
+			// Materials sample aoMap from UV set 1 and other maps from UV set 0 - this can't be configured
+			// However, we will copy UV set 0 to UV set 1 on demand for aoMap
+			if ( mapDef.texCoord !== undefined && mapDef.texCoord != 0 && ! ( mapName === 'aoMap' && mapDef.texCoord == 1 ) ) {
+
+				console.warn( 'THREE.GLTFLoader: Custom UV set ' + mapDef.texCoord + ' for texture ' + mapName + ' not yet supported.' );
+
+			}
+
 			if ( parser.extensions[ EXTENSIONS.KHR_TEXTURE_TRANSFORM ] ) {
 
 				var transform = mapDef.extensions !== undefined ? mapDef.extensions[ EXTENSIONS.KHR_TEXTURE_TRANSFORM ] : undefined;
@@ -2157,7 +2165,6 @@ var GLTFLoader = ( function () {
 
 		if ( material.aoMap && geometry.attributes.uv2 === undefined && geometry.attributes.uv !== undefined ) {
 
-			console.log( 'THREE.GLTFLoader: Duplicating UVs to support aoMap.' );
 			geometry.setAttribute( 'uv2', new BufferAttribute( geometry.attributes.uv.array, 2 ) );
 
 		}