Hi Phil, any irregularites in the vertex normals will especially show up in areas with specular highlights in them or with reflective materials.

You really want to just be using those normals for shading instead of calculating anything by smoothing groups at all.

Here's a comparison from loading that exact same OBJ file into Cinema4D, which does utilize the vertex normals stored in the file for shading - as you can see it gives a "perfect" result - every area is shaded exactly the same as the original NURBS data, that's the kind of high quality that you get if using the stored vertex normals :



- Michael