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.
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
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.
+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…
Hi sv,
Yep, would really be great to be able to provide that option for post out of V-ray.
So what you are looking for is a texture map that returns world coordinates X,Y,Z as R,G,B?
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.
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 
Mind you InfoTexture is useful in general as it allows for wordnormals, reflected normals and refracted normals wich can be fun in post
Regards,
Thorsten
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?
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…
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
Regards,
Thorsten
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.
How would it output negative XYZ values? AFAIK HDRIs only support positive floating points?
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.de/2009/06/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
Regards,
Thorsten
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?
Well technically you can store any vec3 value or any 3 floats per element.
If a Particles Birth position is available at a certain frame is over my head heh.
Regards,
Thorsten
Looked at the image you posted instinct and thought about an upcoming job where some heli shot footage will be tracked to insert fireworks being launched.
Think using track points for particle birth positions would be good and a world position for relight in post would be great… Great stuff.
Check out Nathan’s reel for some awesome use of Worldpositions in nuke (for the movie 2012):
http://www.nfxplugins.com/downloads/nathan\_dunsworth\_2009\_hd720.mov
Regards,
Thorsten
Impressive stuff.
MasterB; 
If it’s a help, in Mental ray you can do this by assigning a texture to your scene using the XYZ Generator in a standard Mental Ray shader’s Surface slot. Set the CoordinateSystem to 3, for World XYZ, and you can get the ‘Position’ pass…