Hi DesuDeus, here's what I get using the built-in importer with your same .obj file and using built-in render:




I can't see any hint of problems there at all, so that tells me that you're probably looking at some stuff specific to Maxwell and you'll likely need to get some tips from the Maxwell forum for how to tweak things to make it happier.

You also might try putting in just a plain sphere created directly in C4D and rendering it at the same time, do you get the same kind of artifacts there? If so then it's something related to render settings or the HDRI you're using and nothing to do with geometry transfer at all.

- Michael