GI with prepass problems

[gardeler]

We are trying to get flicker free GI on an animation with moving objects. It works well for the objects in the forground, but not the ones in the far distance. (we are using irradiance cahce with brute force using the animation prepass.) It is not the small objects in the distance that is causing the problems, but the bigger surfaces. We are trying to up the subdivs, and are now trying to switch to lightcahe for the secondaries with world scale on.

Does anybody know of some better settings for this? Are we doing something wrong here? Is there a way to oversample some specific objects?

(note: the flickering objects are actually non moving...)

Thanks

Marre

[gardeler]

Found this post on the Max part of the forum...

How to render a scene with animated characters without flickering?
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Set the Irradiance Map to single frame Mode,
start with the medium animation preset but change the "Min rate" to -1 and HSph. subdivs and Interp. samples to 90

Set the Light cache to single Frame Mode, set Subdivs to 2000,
check "Use Lightcache for glossy rays" to speed up rendering if you have glossy materials.


Haven't tried it yet, but is that really the recommended settings? Sounds a bit strange to me, but why not.

[LarsSonparsson]

Yep, sounds weird to me too.
Let us know how it worked.

In Max, there is option "use irradiance" in materials.
If it's unchecked, that current material is rendered with brute force.
That way you could create different materials for distant objects and get
them rendered with brute force.

Not sure if Maya has that option.

[gardeler]

Thanks Lasse. I'll check if that option is available in Maya. Whatever results I find on this issue I will post here as this seems to be popping up now and then. But I can't seem to find a proper answer.. Anyways stay tuned..

[gardeler]

Ok.. so I went through the scene to look for possible errors again. I noticed that the shader attached to the flickering object was a maya lambert and not a VaryMat. Obviously I thought that was the issue and we were just about to bring out the champange when we noticed that it was still flickering after changing the shader. (a lot less though..) So the issue is still unresolved...