En parallèle, sur le site Maxon en fin de news :
"Together with this service release you can also download the trial version of the NVIDIA IRay plugin directly in Cinema 4D"
https://www.maxon.net/en/news/maxon-...e-immediately/

http://www.nvidia.fr/object/iray-for-cinema-4d-fr.html

N'ayant pas de nvidia…