about VRayObjectSelect and VRayMtlSelect...

[chib]

I haven't tried "VRayObjectSelect" yet, but does it work just like "VRayMtlSelect"? in that case it seems useless to me, and I guess to many people. I mean how are you supposed to use it in a comp since it has no alpha (for the VRayMtlSelect at least). What would be nice, would be a renderelement that outputs only one channel (less space used) and that would be the object's mask, since you already have its rgb values in the rgb output!
It would revolutionize the way people output masks for compositing: they would be included in exr files and selected by their name...
For the moment I can't see any use for these 2 RE (in the case VRayObjectSelect outputs the same as VRayMtlSelect, but I guess so...) while they could be my prefered ones!
Paul.

[Dariusz Makowski (Dadal)]

Heya

I had that same problem few months and mins ago. The solution is easy... its the first filter in filter list, Multimattechanel or something like that... big LOOONG word. Use it to get Mask just like in Mental Ray Mask. Its not black n white tho.

Back to vrayobjectselect and vraymtlselect, maybe one of them is AA and another one not, duno... I didnt rly spend too much time on them

[chib]

Hell, how could I've miss that!
that's cooooooooooool!!
many thanks!
Paul.

[instinct]

ObjSelect does create an additional element that has the corresponding alpha. When set to raw mode it even creates unpremultiplied output + alpha + filter element (for transparent objects in front of the objects part of objselect)

Regards,
Thorsten

[vlado]

I haven't tried "VRayObjectSelect" yet, but does it work just like "VRayMtlSelect"?

Nope, not quite. It has two modes, "Normal" and "Raw"; in the "Normal" mode it works like VRayMtlSelect, and in the "Raw" mode it creates three elements instead of one: an unpremultiplied RGB element with the object; a floating-point alpha element, and a RGB filter element (includes masking from transparent or refractive objects).

Best regards,
Vlado

[chib]

Wow, it's more like an upgraded "VRayMtlSelect", which would use objects' IDs instead of materials! So it outputs 7 channels in "raw" mode? I'm curious about how Nuke manage this
Thank you guys for the explanations (especially for the multimatteelement tip ), and I apologize for talking before having tested the thing for real : /
Paul.

[instinct]

It doesnt output a single layer with 7 channels (vray currently only supports up to 3 (rgb) channels per element). Instead there are 3 distinct elements automagically created that contain the rgb, the alpha and the filter. So in nuke you basically end up with:

VRayObjectSelectName
VRayObjectSelectNameAlpha
VRayObjectSelectNameFilter

Kind Regards,
Thorsten