Compositing vrayelements and Generate GI

[BcM]

Hello,

Recently i started combining my VrayElements in Fusion to recreate my beautypass.

After careful testing and reading up on it, i read that the best thing was not to use the raw passes, this due to small black/white halos that might appear around objects (due to multiplying).
However, when using this i found out that the normal GI Element doesnt carry material/object "receive GI" and "generate GI" with it. The raw pass however does do that.
Because of this i am left with the choice of:

a) having a composited beauty pass with random halos
b) having a composited beauty pass in which my receive/generate GI on material/object properties do not apply

Is this a bug? Am i missing something?

With kind regards,BcM

[BcM]

No answer so i'll try to elaborate the problem.


1) is the beauty pass. Not much of a beauty but hey, its one
2) The difference between the composited image with GI pass and the beauty pass.
3) The difference between the composited image with RawGI pass and the beauty pass.

As you can see the mortar in two is different with the GI pass. This is because it has a receive/generate GI in the VrayMtlWrapper. How come the RawGI pass does take it?

Anyone?

[Swahn_Kung]

Speaking of halos, are you sure you composite the passes correctly?
None of the passes should have alpha information, that is, they should be rendered out against a black background with just the RGB channels.
Then you use a VrayAlpha pass to mask all the composed passes. Make sure to unpremultiply the composition afterwards.
Perhaps that can help you get rid of the halo/fringing at least?

I always did this error back in the days, saving out the alpha information with all the passes. And naturally I ended up with "mysterious" edge halos I couldn't get rid of.
It might be possible to composite passes with alpha but I think it's faster with alpha-less passes. Faster to work with and faster to compute as well I believe.

I hope this helps a bit.

[BcM]

I wish to avoid using the raw element all together. Yet the normal GI element doesnt work too well with the vraymtlwrapper. Or so it seems.

But thanks for the advice, because i didnt think of removing the alphas. It might remove the halos near the alpha, but these halos mostly around reflective/refractive objects. Where the diffuseelement has no color info (Just black).

[Zdravko]

Could you please attach the scene or send it to: support@chaosgroup.com?

[DanielBrew]

If you are using an anti-aliasing filter try turning it off in Render Setup > V-Ray > Image Sampler. Multiplying two anti-aliased passes can cause halos.

[fxi]

but these halos mostly around reflective/refractive objects.

http://vfxvault.com/tutorials/nuke_c...ch_01_h264.mov

[Wobi]

Thx for the vid, very helpful.