GI colored shadow on matte objects

[FSGFX]

Hi!

I have a small problem when working with matte objects and shadows being cast onto them when using any form of GI.
This is a quick example of a dummy scene with a VRay Sun & Sky in it.
The render comes out like this:


Now I am rendering our the plane alone and as a second pass the sphere with the plane set to a matte object (alpha -1, affect alpha, shadows).
The result looks like this:


2 things are looking different.
1-) the color bleeding is slightly off in the comped image.
2-) the shadows have lost their color and are darker.

Is there anything I should do different?

Thanks,
Flo

[FSGFX]

The problem is still here.

Looks like matte objects are not affected by Gi in the shadow area.
Im missing the orange color bleeding.

any ideas.?

[Morbid Angel]

are you saving your passes as float?

[FSGFX]

16 bit exr files...
even if i check it direct in the vray frame buffer there is no color info in the shadow... only pure black...

[RockinAkin]

Has anyone found a solution to this? I'm having the same issue.

Surely there's an easy / correct way to use the Matte/Shadow object properties for compositing.

VRay seems to be attempting to store this GI-influenced shadow color and GI bouncing as a RGB colored Alpha channel (not just greyscale) - which you can see in the VRay VFB.
However, most file formats and compositing packages I know of only allow for a greyscale 0-1 alpha channel... so I'm not sure how to use this data at the moment.

[Zdravko]

Looks like matte objects are not affected by Gi in the shadow area.

This is a known issue. For the moment we are discussing different approaches to workaround it.

[RockinAkin]

Thanks for the quick response Zdravko.

I'm sure you hear this often, but please make this a high priority item - as it makes layer-based compositing with VRay very difficult at the moment.

[rikou]

+1
It'll be very convenient