Adds a check for the instance when normals are provided as part of the vertices element in the collada file and supplies the normals from there (as per the collada spec). If normals still aren't supplied, this defaults to calculating the vertex normals via Geometry.computeVertexNormals().

src/extras/loaders/ColladaLoader.js

@@ -2230,7 +2230,13 @@ THREE.ColladaLoader = function () {
 
 		this.geometry3js.computeCentroids();
 		this.geometry3js.computeFaceNormals();
-		this.geometry3js.computeVertexNormals();
+		
+		if ( geom.calcNormals ) {
+			
+			this.geometry3js.computeVertexNormals();
+			
+		}
+		
 		this.geometry3js.computeBoundingBox();
 
 		return this;
@@ -2325,13 +2331,38 @@ THREE.ColladaLoader = function () {
 
 			var face = null, faces = [], uv, uvArr;
 
+			if ( ns.length == 0 ) {
+				
+				// check the vertices source
+				input = this.vertices.input.NORMAL;
+
+				if ( input ) {
+
+					source = sources[ input.source ];
+					numParams = source.accessor.params.length;
+
+					for ( var ndx = 0, len = vs.length; ndx < len; ndx++ ) {
+
+						ns.push( getConvertedVec3( source.data, vs[ ndx ] * numParams ) );
+
+					}
+
+				}
+				else {
+					
+					geom.calcNormals = true;
+					
+				}
+
+			}
+
 			if ( vcount === 3 ) {
 
-				faces.push( new THREE.Face3( vs[0], vs[1], vs[2], [ ns[0], ns[1], ns[2] ], cs.length ? cs : new THREE.Color() ) );
+				faces.push( new THREE.Face3( vs[0], vs[1], vs[2], ns, cs.length ? cs : new THREE.Color() ) );
 
 			} else if ( vcount === 4 ) {
-
-				faces.push( new THREE.Face4( vs[0], vs[1], vs[2], vs[3], [ ns[0], ns[1], ns[2], ns[3] ], cs.length ? cs : new THREE.Color() ) );
+				
+				faces.push( new THREE.Face4( vs[0], vs[1], vs[2], vs[3], ns, cs.length ? cs : new THREE.Color() ) );
 
 			} else if ( vcount > 4 && options.subdivideFaces ) {