A new wrapper texture named "TexSelector" is available from version 13.17.
It has the functionalities of a simple 'multi texture', and uses the Material ID set in the mesh.
Polygons set with Material IDs from 1 to 10 will use the textures 1 to 10.
It has up to 10 slots for any Texmap, color or gray value.
Usage:
Texture count: Set the number of textures to use. This should match the number of material IDs used in the mesh.
Use Instance ID: If enabled, will shift the assigned texture using the object's instance ID.
Texture 1 to 10: textures to assign.
Reference Objects rollup:
Once the material using this TexSelector is assigned to a scene object, you just need to press the 'Refresh object' button.
A list of all objects using this texture will be updated.
If the 'Fix issues' button is displayed, press it to setup the geometry automatically.
How it works:
The TexSelector currently uses a vertex attribute set in the geometry automatically by the Octane Geometry Modifier.
This vertex attribute is set to each polygon using it's Material ID.
It is later used by the internal OSL texture to switch the corresponding texture.
Pressing 'Fix issues' will create and configure the Octane Geometry Modifier correctly to use the Material IDs as a vertex attribute.
Notes:
-You can set ALL the textures types at once, to be Texture, Color or Value using the context menu on one of the Texture type combo box.
-Another Octane texture named "Multi-Texture" has the specific purpose of assigning texture randomly.
-As for any Octane texture and material, you can now select any non-octane textures as input, if you enable 'Any plugin Texmap' and 'On-the-fly Material Conversion' in Octane Preferences / Material tab.
-The expected settings for the Octane Geometry Modifier's Generator is 'Mtl Index'. Other settings are accepted, but might not give the correct result.
-In a later update, the use of the vertex attribute won't be needed anymore, and the Reference Objects rollup will be removed.
Known issues:
-The 3dsmax viewport display of 'TexSelector' is incorrect.
-When using 'Use instance ID', changing the instance ID in Octane Object Properties do not update the Octane viewport instantly. You will need to press the Update or Rebuild buttons.
-You currently can't use Octane random 'Multi-Texture' on an object also using 'TexSelector'.
Samples:
Video: