Disappointed day today. After doing A LOT of rendering and then editing of image sequences I discovered -the hard way- that setting the raytrace shadow rays to 5 and ray depth limit to 2, is just not high enough and I've ended up with noise in the shadow that doesn't look bad in a single frame but is pretty distracting on the video playback.
Ugh I spent so much time already testing out these lights in Mental Ray still to come up short in the quality results :( Doing more tests today to see what I can do to improve. Unfortunately I doubt I will be able to re-render all the shots I've done for the MPS deadline, especially since that renders times would be doubled with higher quality settings and the grain will be certainly reduced, but may still be present in the playback even with ray trace setting 4x higher. I have more animating and more rendering to do yet, so I must forge ahead! I'm finding something of a compromise by only increasing the levels of the practical light in the living room, which produces the most noticeable shadow of Malcolm on the couch.
(The first image is using 20 shadow rays and a depth limit of 5 with a render time or 4mins 11sec, while the second uses the settings described in the paragraph above with a render time of 1m 58sec. In the last image only raytrace/depth limit is increased (20/5) on the practical living room ceiling light with a render time of 2m 26sec.)
Richard Cunningham - IHM Founder