Matte Object Weird Behavior

[caustikstudios]

Hello Everyone,
I hope someone can help me out with this problem.
Please check the attached image split in 2

On one side, the image is rendered normally
On the other side, all objects except for the teapot have the following vray properties:
. Matte object: checked
. Matte for Refl/ref: not checked
. Alpha: -1

Direct Light
Affect shadows: not checked
Affect Alpha checked

All other properties are kept at their default values.

Both images are rendered with linear color mapping, no change to multiplier or burn value (1.0 / 1.0)
Also, all VFB color corrections are turned off.

As you can see there is a big difference in the lighting in both images. Why?
Incidently, if instead of Matting the object, i choose in their "Object Properties" to be not visible to camera then the lighting matches - (at the expense of invisible object no longer "matting" my visible objects)

Anyone has any idea?

PS: using vray 3.10.01 on Max 2014

Cheers

[tashko.zashev]

Hi,

It would be best if you can share the scene file as well. Then we can try to find what make the lighting difference in both setups.
You can post it here or send to support@chaosgroup.com.

[caustikstudios]

Hello Tashko,
I've stripped the scene of all details (textures, models, etc...) to see if the problem persists and it does. Here are 2 files. one with matting, one without and the rendered image.


Matte_issue_max.zip


Thx

[tashko.zashev]

I think all you have to do is to untick "No GI on other mattes" option for the mattes.