GI noisy animation

[t3dm]

Hi all,

just doing an animation based (multiframe incremental Irradiance map/flythrough lightcache)

low settings on the GI.. and no apparrent noise on most of the renders. Normally I will hide glass etc but just down to time and the what we have modelled this project I haven't hidden the glass from the GI prr-calc.

just looked at the GI pass and the glass and floor is really noisy, time wise I can't up the Irr map settings much, and it's not really affecting the scene anyways... we have an AO pass anyway for finer details.

just wondering about GI and Glass again.. what's other peoples workflow?

[joconnell]

Could you post your reflection and refraction pass from the render? What I'd say it is, especially on the glass areas, is that vray never bothers putting in any effort in areas that don't contribute much in the final image. In your example, both gi and light only have any major contribution to surfaces that are opaque. With glass being transparent, all of the light passes through it, as opposed to light falling on it and causing shading. All of the detail in your glass is likely in the reflection and refraction passes which should be nicely sampled, but your raw light and raw GI passes are likely to be a bit trashy. What'll happen though is if you're going through a comp workflow with passes and combining your raw GI or raw light with the diffuse filter, the glass areas in the diffuse filter will be nearly black. When you multiply your raw GI or raw light by this pass, the blotchy glass areas will get multiplied down really heavily by the black glass areas in the diffuse filter and so it won't be very visible any more.

[t3dm]

[t3dm]

yep.. normally in certain senarios I get rid of the glass to keep the GI clean... just so I can use the GI pass for some post stuff, but due to the nature of this project I have gone down a much more simple route.

[joconnell]

Yeah the GI is a bit shitty on the floor which is probably down to your low settings, the glass GI won't end up coming through at all since any of your light passes multiply over the diffuse filter, and the diffuse on really reflective things or really refractive things is pretty much black.