wizzackr
01-15-2007, 05:48 AM
ok, for an architectural project we need a lot of savannah to be rendered out in HD (the bloody buidling is sitting right in the middle of nowhere). to do the savannah/blades we used the 'grass' fur pre-set and customized it to suit our intention - nothing too fancy, certainly not realistic.
we render all passes with MR, and the renderlayer for the grass only contains the fur (not even the feedback shape), a use background shader beneath it for compositing purposes and a directional light. fur render option is set to volume, sampling currently at 1,3 @ a contrast set to 0.05,0.05,0.05 in the render globals, still the scanline renderer, no rasterizer. now in the animation we get some serious high frequency noise, which gets worse the further you get to the horizon line - close up to the camera, where you can really make out single blades, everything works ok. we have had similar issues with the very fine displacements on an ocean before, which we blurred out in compositing with a zDepth pass. this does not work here, though, due to the higher contrast in the flicker as well as the fact that we do not want any blurriness in that particular shot.
we already set the noise frequency and amplitude to 0 for tip and base color in the fur description, as i read here on the forums this could cause noise (albeit low-frequency IIRC).
hence my question: how do i get rid of this annoying flicker? brute force and increase sampling? if so, how hight do we need to go and what filter is best for this? or am i missing something fundamental here and the fur sampling is set somewhere else and does not even obey the RG settings?
any help is greatly appreciated, guys - we'er really at a loss here :(
we render all passes with MR, and the renderlayer for the grass only contains the fur (not even the feedback shape), a use background shader beneath it for compositing purposes and a directional light. fur render option is set to volume, sampling currently at 1,3 @ a contrast set to 0.05,0.05,0.05 in the render globals, still the scanline renderer, no rasterizer. now in the animation we get some serious high frequency noise, which gets worse the further you get to the horizon line - close up to the camera, where you can really make out single blades, everything works ok. we have had similar issues with the very fine displacements on an ocean before, which we blurred out in compositing with a zDepth pass. this does not work here, though, due to the higher contrast in the flicker as well as the fact that we do not want any blurriness in that particular shot.
we already set the noise frequency and amplitude to 0 for tip and base color in the fur description, as i read here on the forums this could cause noise (albeit low-frequency IIRC).
hence my question: how do i get rid of this annoying flicker? brute force and increase sampling? if so, how hight do we need to go and what filter is best for this? or am i missing something fundamental here and the fur sampling is set somewhere else and does not even obey the RG settings?
any help is greatly appreciated, guys - we'er really at a loss here :(