at2 software has developed and released a demo version of M4D, a version of Mental Ray for Cinema4D. Check it out HERE.
“mental ray® is a rendering software which generates images of outstanding quality and unsurpassed realism. It combines the physically correct simulation of the behavior of light with full programmability for the creation of any imaginable visual phenomena. The software uses advanced and proprietary acceleration and sampling techniques for faster rendering on even the smallest, single processor machines.” -www.m4d.com