Hi,
Renderman and MentalRay 3.9 give the possibility to control some shaders (or position or other) with extra attributs on some nodes :
http://forums.cgsociety.org/showpost.php?p=6944211&postcount=36
It is useful to manage “big scene”.
What’s about Vray ?
In “to do” list ? 
Yes, you can attach custom data to shapes and nodes in the most recent nightly builds; however you can also use a regular switch node to do the same thing.
Best regards,
Vlado
Yes i can use a switch node (like renderman or mentalray), but the idea is to have an “asset” with the information in the asset (like : this asset will be more desaturate), in an extra attribut.
It is a “workflow” for big scene.
When you say : “you can attach custom data to shapes and nodes in the most recent nightly builds”, you talk about “User Attributes” ?
If yes, can you give me an example like : i have 2 spheres, 1 material. 1 sphere will be green and the other red, with user attributes please ?
Hard to found how to use user attributes, the doc say :
User Attributes
Allows the user to create their own attributes
Thank you Vlado !
I tried to write :
color_tex=AColor(0.0, 1.0, 0.0, 1)
or :
BRDFDiffuse VRayMtl1@diffuse {
color=Color(0, 0, 0);
color_tex=AColor(1.0, 0.0, 0.0, 1);
}
in the User Attributes but it isn’t work.
I don’t knows the syntax.
Hi,
Anyone have the answer please ?
I try different syntax, i don’t found.
Hm, sorry it looks like this is not yet in the builds - you can add the user attributes, but there is no way to utilize them just yet - we will add the missing parts tomorrow. But in general, it would work this way.
First, you add the user attributes to the shape that you want, and put something like mycolor=0.5, 0.6, 0.7
After that, you create a VRayUserColor texture node (which is the missing part for the moment), and specify mycolor as the name of the user attribute. Then you can use this texture anywhere you would normally do it in a shading tree - for example you can attach it to the diffuse color of a material.
Best regards,
Vlado
Vlado, is that a nightly build update or stable build update?
All changes first go into the nightly builds; if they seem to cause no issues and are confirmed to work properly, then we merge them into the stable builds. The changelog contains a list of issues for the nightly and stable builds respectively; nightly builds contain all changes from the stable builds, but the reverse is not true.
Best regards,
Vlado
Hello Vlado,
Where can we gain proper access to the Nightlies ?
Best regards
You can email either vraymaya@chaosgroup.com or vlado@chaosgroup.com
Best regards,
Vlado
Thanks ! I just did 
Hi,
It doesn’t work for me.
When i connect a VRayUserColor in the diffuse slot on a VrayMtl, i have : [2011/Jun/6|18:00:55] V-Ray warning: Unsupported texture VRayUserColor
V-Ray for Maya version 2.10.01 from May 29 2011, Maya 2011, Linux64
?
Can you post your scene here? Works for me…
Best regards,
Vlado
Hi,
It works well for me.
But users attributes attached to mesh seem to be lost when they are exported to proxy
Yes, this will happen for all custom attributes as the original shape is deleted and the proxy is attached in its place. Will make a note to fix this. As a work-around, you could try assigning the attributes to the transform node of the object rather than the shape.
Best regards,
Vlado
It is working on Maya 2010 Linux64, May 29 2011, but not in Maya 2011.
Strange.
I will retest.
Ok, it is working with Maya 2011. It was just bad environments (Maya 2011 loaded plugins from Maya 2010 -_-).
Do you think a “VRayUserString” will exist ? (to set a different texture path for example). Currently we connect a VRayUserScalar in the “Image number” of a fileTexture.
A “VRayUserString” will be great, with can conenct after for example “VRayUserString.output” to “file1.fileTextureName”.
I’ve made a note to implement this, but it is not yet done.
Best regards,
Vlado
Has this progressed any further? It would be a really nice feature with many possible uses.
When connecting a VRayUserColor to the diffuse of a VRayMtl it immediately crashes my Maya 2012 SP1. It’s the same for all the latest nightlies and the latest stable, all on OS X.
/Max