Crash : use VRayDirt in displacement

[bigbossfr]

Hi,
I want to add displacement on edge of a model. For this, i use VRayDirt with "invert normal" on, and in the occluded color, i connect my map.
The problem : Vray crash.

V-Ray: V-Ray for Maya version 2.25.01, revision 19321 from Feb 13 2012, 07:40:14, linux64, Maya 2011.
(perhaps now it is fixed on more recent build ? I will test today when i will have the new install at my work)

Thanks.

[bigbossfr]

Ok, same problem with the build from today.
If we can fix this quickly, it will be great.
Thanks.

[Neilg]

This is why the distance tex was implemented I think - the way dirt works means you cant use it for things like displacement.

[bigbossfr]

I don't know if the VRayDistanceTex do what i want.
I use VrayDirt with normal invert to get the edge of my object. Can we do this with the VRayDistanceTex ?
And the VRayDistanceTex is not in Maya..

[instinct]

This would create an impossible dependency, hence does not work. The displacement would alter the dirt which would alter the displacement etc. etc.

Regards,
Thorsten

[vlado]

If we can fix this quickly, it will be great.

Unfortunately it is not fix-able. (Well, we could fix the crash, but it still won't get you the effect you expect). As Thorsten pointed out, it creates a dependency that cannot be resolved. One solution would be to bake the VRayDirt texture, and then use that as displacement.

Best regards,
Vlado

[bigbossfr]

Yep, i will bake the VRayDirt, this is the solution.
Just a suggestion/idea : what do you think to add an option in the VRay dirt to bake the map internally before to rendering (like a "prepass") ? (Renderman style heyhey)

[vlado]

Yep, i will bake the VRayDirt, this is the solution. Just a suggestion/idea : what do you think to add an option in the VRay dirt to bake the map internally before to rendering (like a "prepass") ? (Renderman style heyhey)

For the moment, I'd rather not. It will bring in a whole host of other issues...

Best regards,
Vlado

[ultrasonic]

this smells like the ideal application for baking into PTex!!! Does Vray support that already? This would be even more awesome than baking into vertex colors!!!!

my 2 cents
Oli

[vlado]

No, we don't have any experience with PTex writing just yet; also, we had to implement texture baking for subdivision surfaces first, before we can think of PTex baking (which would have to be be an entirely separate baking engine).

Best regards,
Vlado