What is the specific role of User attribute support in VRayDecal

[123456_]

I don't understand what the updated feature today is specifically for. Can someone demonstrate it

[viktor_angelov]

Hello 123456_

This will allow the VRayDecal to export user attributes and also to expose the option for switching between the user attributes of the object and the decal.

[123456_]

Hello 123456_

This will allow the VRayDecal to export user attributes and also to expose the option for switching between the user attributes of the object and the decal.

Thank you for your reply. Can you demonstrate the specific usage method? I don't quite understand

[boyan]

Nihao,

You can try the test scene attached here. Some parameters are animated keeping this in mind. Update the bitmaps in the multisubtex as well.

Cheers,

[123456_]

Nihao,

You can try the test scene attached here. Some parameters are animated keeping this in mind. Update the bitmaps in the multisubtex as well.

Cheers,

Thank you very much. I now know the purpose of this option

[akos_kiss]

Hello boyan
In the file you linked there is a second xpresso setup (Null object name: Expression) but the object node in the xgroup is empty. Is there a reason for this or is just a mistake?

I'm really interested in knowing more about utilizing vray user attributes ( in materials, render passes, objects) , but so far it was unclear to me on how to achieve this. I think it would be great to have some documentation on these features.

the obejct named "V-Ray Decal" uses one of the presets from the dropdown menu. I can see the vray object id and vray object name in the "Random User Attr Name" field. As i understand this the Decal object reads data from the shader, where the shader gets this info from the objects it is applied to. Is this correct?

If i want to animate these attributes i have to create a user Data field and use the name "Random User Attr Name" with the vraypresetstring field. Do i understand this correctly? Can i use any object to create the new user data field to drive the shader or did you use the annotation tag for a specific reason?

Further questions:
How does the "VRAY_MOGRAPH_ALTERNATIVE_ID" work? how can i use it?

If i use the vray mograph index i get the same colors in the decail for the cloner indexes 2 and 4 ( Cloner.1). why is this?

I tried using the user integr and user scalar nodes in the node material with vray object id attribute but it didn't work. Is there some kind of workaround for this to use it directly in shading?

I have a bunch of objects with different names and hierarchy. i would like to create different combination of "groups" for these elements and use these in material attributes and/or render elements. Can i stack multiple annotation tags or add multiple rows of user data to and objects and drive attributes with these? Using the object id tags or object name doesn't have this flexibility.
An example for this:

I have objects 1,2,3,4,5,6
I would like to drive attributes for the following custom groups
selection set 1: {1,2,3} {4,5,6}
selection set 2: {1,2,3,4,5} {6}
selection set 3: {1,2} {3,4} {5} {6}
Would something like this be possible to create? if yes could you give an example?

The last question is probably a bit out of reach but would it be possible to drive these attributes from different parameter values? for example, i have a bunch of object with roughess values of, 0.2 , 0.5 and 1. could create "ids" for these separate elements to drive randomization?