Though I haven’t made a small tutorial about using FG (should I have done before released) I want to mention an important factor that have to be taken into account: Normals
normals have to point at the same side where ligt is, for example in a typical cornell box scene the interior small boxes should have thier normals in the default creation direction, that is , outside them , but for the enclousing box, the walls, normals have to be inverted pointing inside.
If some scene give you troubles try with normals. I will upload soon a small tutorial if someone don’t do that first because many people are already experts in FG 🙂
I’m gladd even that some issues have being fixed, thanks to all 🙂