Luca, you have to do it in AutoCad, before export, in AutoCad, go to tools, options, change your arc and circle smoothness to 400, change your segments in polyline curve to 16, change your rendered objects smoothness to 10, change contour lines per surface to 8, when you export the model out as a 3ds, you have to change the 3ds option box, the auto smoothing to 120 degrees....then you should see a huge difference. Sharen