multisub texture support

[BVA]

I see the multi sub texture are added, thanks.
How does it work? Would you mind sharing a sample or just explain the workflow?

[vladimir.nedev]

I have added it mostly to support importing it from a .vrscene created in V-Ray for 3ds Max. Specifically for the V-Ray Object ID mode.
Some of the modes might not be as useful in V-Ray for MODO as they are in V-Ray for 3ds Max, because there are alternatives or you have less control.

I will explain:

Face Material ID - in V-Ray for MODO the face material ID is automatically assigned based on material/part/selection tags. The IDs start from 0 on each mesh.
So if a mesh has 4 materials, it will have IDs 0, 1, 2 and 3. You can't control this, like you can in 3ds Max from the Edit Poly modifier.
For this reason this mode might not be very useful in MODO. Instead you can use masks in the Shader Tree.
This mode is somewhat similar to the Item mode from MODO's Variation Texture, which we don't support yet.

V-Ray Object ID - you can specify the object ID in the V-Ray Geometry Properties, at the very top. This mode works the same way as in V-Ray for 3ds Max.
In MODO you can use item masks in the Shader Tree instead, but the Multi Sub texture can be useful if you are texturing sub-materials in the Schematic (until
I add the ability to specify the textures of sub-materials in the Shader Tree).

Random by Render ID - each item gets assigned a Render ID at the start of rendering, and the random values generated start from 1 up to the highest ID value specified in the Mutli Sub texture.
You can't control the randomization and it will change as items are added/removed.
There are a few more modes similar to this one (Random by Node Handle and Random by Name), which require changes to how geometry is exported, so I haven't added them for now.
Since they generate the random numbers based on something that doesn't change (unlike the Render ID) they might be more useful.

The nice thing is that all currently available modes work in RT GPU.

Greetings,
Vladimir Nedev

Edit: actually the Item mode from MODO's Variation Texture is basically a random value based on Face Material ID + Render ID.
I don't think we have an equivalent mode at the moment.

[vladimir.nedev]

Here are some very simple example files.
Note that for the Face Material ID one I have applied material tags that don't do anything (they contain a black texture set to luminous color).
This way I am forcing V-Ray for MODO to assign different material IDs on these polygons.

vray_multi_sub.zip

Greetings,
Vladimir Nedev

[BVA]

Thanks Vladimir.