Rick ive since found that the number of bounces in the FG rollout may not really do a lot
there are other things you can do that will make more difference…at the time i just had the bounces set higer and posted that but i could probably set them back to default and still get less flickering.(havent tested this yet - have deadline approaching)
[i tested it back at 5,5,5 and it was fine ]
the FG bounces may be intended for when your using a HDR map …possibly
i have made the scene brighter slightly by adjusting the physical scale settings in the environment panel exposure controls (render the little preview window and upped the physical scale amount)
the example that ive seen of jeffs MR webpage i checked again, and he was increasing the photon bounces to lighten the indirect areas not the FG bounces, -my bad
since checking what the FG bounces actually do it seems that if you make thema higher number then the results are negligable (just adds time to render without delivering a lot of noticable difference…Fg does most of its work on the first pass according to FG section in the 3dsmax7/help/mr_manual.chm
possible alternative to this is to increase the FG filter size to 2 or 3 (not higher than 4) i havent checked this yet… as it looks like MR already has an internal de-speckler (flicker killer)which is on by default (set to 1) im guessing if you made it two then it would do more averaging and give a smoother result…
people usually already do this another way by blurring the HDR image (if your using one) a bit to start with so there isnt any sharp changes between pixels in the HDRI image in the beginning you will find most free HDR images are already blurred slightly.
GI photon maps are good for indoor scenes, mines outdoor (in open space) so a lot of photons would just bounce off into nowhere
the main thing was to turn off rebuild, but still use a map, as it seems it will build a map on the first frame and reuse it for the others…this takes out a lot of flickering just doing this. and its not re-calculating it all on every frame (where the flickering comes in)
this would make sense because if i was a large studio id be rendering out a background pass on the farm as one set of footage (not much moving other than camers) and rendering out the characters seperately so i could control and tweak them better in the composite later on…possibly
Pixars website used to have a section “how we make movies” i havent looked in a while but it may still be there…generally they render everything in passes (like render elements in max)
I havent tried to use MR with the command line but there seems to be a utility that can merge FG maps, so what you would do is render out several keyframes where the FG map would be desirable and use this to merge into one FG map that you use for the renders.
seems a bit more of a manual approach but could save proccessing time.