VrayMatteShadow - Atmosphere and ZDepth

[DuskZero]

I'm writing out to EXRs direct from Vray's write to Raw Image File output in the Frame buffer rollout.

I'm trying to render trees on one pass, which should be matted out by buildings objects (set to Matte, Alpha -1.0 in the Vray Object Properties). When rendering this pass with atmosphere or Z-depth, the matte objects show in both channels. With atmosphere (fog) on, they also show as semi-transparent in the alpha channel.

This is making it difficult to comp in fogging and volume light, as I can't get a clean Z-depth nor atmosphere path to composite.

So what I'm asking for is:

Vraymatteshadow objects should not show in atmosphere or Z-depth - or have a checkbox to turn this on and off.

Any help gratefully received.

[vlado]

Well, for the atmosphere part is easy, simply disable the Apply atmospherics option in the object's node properties.

For the z-depth, you can assign some objectID to the matte objects, render an objectID pass and then use it to mask the z-channel where you don't need it.

Best regards,
Vlado

[DuskZero]

Hi Vlado,

Thanks - I'm rendering out Object ID passes and will use them to cut out. Is this intended behaviour, then? The velocity channel also shows the matte objects, but we should be able to work around this in the same way.

Cheers,

Sam

[vlado]

Well, I can think of cases where the current behaviour is what is needed; then again there are cases when it is not

I suppose an option to add an object to the buffers or not might be handy in this case.

Best regards,
Vlado