Softimage had a neat “render viewport region” method and I always wanted to have something like that in max. Well, I guess this will never happen officially but I tried to do it with maxscript.
It works, but I can’t stop nor control the renderer after I’ve started the process, I have to wait until it’s finished. It’s fast enough for small scenes but It would be pretty annoying for larger ones… so it’s not really usable. But anyways, was fun to do 🙂