Position pass for "relight" in post

[Mikokariadis]

Is it already possible to generate such a pass with v-ray as is on 1.5 sp3?
I have seen how to use this in Nuke and Fusion and read that it is also possible in other post apps but it wasn't generated from a v-ray render, though I do know you already can get the normals out in passes, I do not know about this "position pass".
I think it is a pass that has something close to what "pixols" are supposed to be in zbrush minus the color/material information.

[instinct]

No this isnt possible atm. We got an in-house version of InfoTexture that offers WorldPosition and can be added as an ExtraTex element.

Regards,
Thorsten

[Mikokariadis]

Hi instinct,

thanks for the info. Was figuring it could not be done atm by looking at the passes available, thought maybe it could be "hidden" somewhere or I was just not getting it.

[sv]

+1 for this being added as a feature request.
I've also been looking into how to get this info out of Vray - have managed it with Mental Ray, but as we use Vray 99% of the time of everything, it's definitely something that is needed...

[Mikokariadis]

Hi sv,

Yep, would really be great to be able to provide that option for post out of V-ray.

[MasterBercon]

So what you are looking for is a texture map that returns world coordinates X,Y,Z as R,G,B?

[Mikokariadis]

Hi MasterBercon,

Believe so. I think that is what would allow the "second lighting"/"relight" process in post. The normals and the camera info can already be exported out. But not the world position.

[instinct]

Preferrably as renderelements i'd guess, but as i had to get it running quick i just tweaked the existing map to output worldcoordinates instead of barycentric :P

Mind you InfoTexture is useful in general as it allows for wordnormals, reflected normals and refracted normals wich can be fun in post :P

Regards,
Thorsten

[Codi]

You can create a mixture of gradient ramps using world coordinates where black to red follows X direction, black to green Y and black to blue Z and then put it into the ExtraTex render element.

Would it work for this purpose?

[Mikokariadis]

Hi Codi,

believe so, though that is way over my head. Will have to take a look at it.

instinct...that is just teasing of the worst kind...

[instinct]

Well everything (including the sources) is available for free besides the world normals pass. So everyone that has compiled a plugin should be able to figure that one out :P

Regards,
Thorsten

[Mikokariadis]

Of the worst kind I tell ya!!!

I only used "no operation" commands to get around jumps in software of sorts...should of kept with it.

[MasterBercon]

How would it output negative XYZ values? AFAIK HDRIs only support positive floating points?

[instinct]

EXR supports negatives just fine. So outputting WorldSpace normals and worldspace coordinates works nice..

Here's another thing one can do in post with them:

http://www.leviathan-entertainment.d...6/tease-again/

That's a pointcloud rendered to nuke's 3D space from a single EXR containing a worldposition element.

Nathan has a far more sophisticated example of that :P

Regards,
Thorsten

[Mikokariadis]

Maybe by using signed float point in an exr? (edit: like intinct stated previously)

Way over my head...

instinct...can that be used for particles birth pos?