You can't see it in these images, but the zigzags are still there, unchanged. I really think that is a C4D problem. Especially since I just did another refractive test with another scene, using the same workflow as when the bubble would fail, and it's perfectly fine. This time, the refractive was a solid glass object, not a hollow one. I am going to test the same object but next with a thin surface instead of a complete solid to see if it behaves like the helmet bubble.
I think it is also possible that there is something intrinsically different about the bubble mesh from other meshes. Even though I have re-xported it from Creo, and the vertex normals are exported, maybe Creo did something unique that is difficult to interpret by other loaders. At any rate, Octane has zero problem with the mesh when it comes straight out of Creo. Unfortunately, I can't then combine it with other meshes easily for the single OBJ that Octane requires.
Thank you very much for your time on this Roeland. Much appreciated.
