nitfus

Thank you very much for your replies. The "edit normals" modifier solved the problem, but I will also try rest of your tips and see how it will work, just to practise:).

I've got a problem with the reflection. I think I've already checked everything, without any good results. I tried putting the simplest vray material, deleting all the scene lights, changing HDRI maps, changing rendering parameters... nothing has helped. The triangles of glass reflect light in a strange way. The weird thing is that rawreflection and rawrefraction passes seem to be alright. Please, help me.