I have veloute 1. I'll try to reduce the scene and post it here. Currently the scene is 57MB. That's a tad much. ;) Render settings are irrelevant. GI, no GI, ray tracing, no ray tracing, pixel accuracy for shadows, object etc. do no change the fact that the arches are displayed improperly. There are 2 lights and they are roughly close together near the center of the four visible pillars. Total intensity amounts to 100%. It should all become evident (I hope) when I post the carrara file. It could well be that the vertex model for the arch is partly responsible for the problem but for the most part it looks fine to me.