Thanks Polax. I have found some - but not all - of the problem using several different applications to run the model through as you have suggested. Subdividing the polys did not help, actually made some undesirable geometry banding in the model. Still can't get all the shadowing fixed, but it is better. I there a setting for shadow bias on either the sunlight or spotlights or is there something about rendering qualaity/resolution I might not understand? I looked around but did not find anything. Many thanks to you. wb