Exclude object's alpha from the scene

[kostenurka]

Hi,

I have 2 objects. In alpha mode I'd like to have object 1 in black (its alpha not participating). Only the alpha of object 2 is what I want...
Unfortunately Alpha contribution (0,1 or -1) under Material Options does not help at all.

Long time ago Fernando has answered with working solution but I can't find it..

Thank you for helping
Best

[georgi.georgiev]

Hi,

Are you using the latest V-Ray 3.60.03? Please be informed that the Alpha Contribution parameter works correctly.

[kostenurka]

Hi Georgi,

Yes I use V-Ray for Rhino, version 3.60.03 adv ( Jul 3 2018 ), except it's running on Rhino5
Not working here obviously

[georgi.georgiev]

Kindly note that we are unable to reproduce the issue.

Could you please make sure that the material is applied to the geometry?

[kostenurka]

Got it.

The alpha contribution plays role only with CPU engine used. GPU (even for production rendering) disables Balck Alpha (-1)

Best

[georgi.georgiev]

Apologies for neglecting that fact. The Alpha Contribution parameter is not supported by the GPU render engine and there are no plans for supporting it soon.