On that object, i ran into a problem i've seen before but that i this time can't solve on my own. The big visible face-structure is the original object resolution. I already tried subd on rendertime and real smoothing (producing a highres mesh). If the aiSurfaceShader is set to roughness = 0, there is no problem. As soon as i increase the roughness, the old face-borders show up.
Scene is currently only lit by a skydome light with an HDR (mirror ball mode).
I tried to unlock the normals, set them to face (which results in facets) and smooth them again - deleting the history inbetween each step - but i end up in the same result.
Any ideas welcome.
Thanks in advance