MultiMap 'Tile ID' (UDIM) Renders Only First Tile

[thetexturedude]

Hello everyone,

I'm having a persistent issue with the UDIM workflow in Corona 13 and 3ds Max 2025 that I haven't been able to solve after troubleshooting. I'm hoping someone might have an idea what's going on.

The Goal:
To use a UDIM texture sequence (BaseColor.1001.exr, BaseColor.1002.exr, etc.) on a single object

My Setup:
    Corona Renderer 13 + Max 2025
    Material: A standard CoronaPhysicalMtl.
    Map: A Corona MultiMap is plugged into the Base Color channel.
            Inside the Corona MultiMap, I've used "Batch load textures..." to load my BaseColor.1001.exr and BaseColor.1002.exr files.
            The "Randomize by" mode is set to "Tile ID".
    UVs: The model has an Unwrap UVW modifier. The UV shells are correctly laid out across the UDIM tiles—one shell is entirely within the 1001 space, and the other is entirely within the 1002 space.

It seems like Corona is simply not respecting the "Tile ID" instruction and is defaulting to the first map in the list for all UVs, regardless of their position. I've also tried unchecking 'Tile ID' still it renders only the 1001.exr texture on all mesh parts.

Has anyone encountered this specific behavior? Are there any obscure Object Properties, Render Settings, or known bugs in this version that could be causing this?

Thank you for your time and any help you can provide.

[romullus]

Hi,

Tile ID in Corona maps is not meant for UDIM textures, it's for its own Corona Tiles map. For UDIMs you need to use Max's MultiTile map.

[thetexturedude]

Gotcha! thanks.

When I use Max's inbuilt MultiTile map, it creates Standard Bitmap nodes. Is there a way to convert them to Corona Bitmap so I can leverage extended settings for connected textures?

[romullus]

You can use Corona scene converter to convert Max bitmaps to Corona ones or the other way round.

[thetexturedude]

Corona Converter worked! thanks so much!

[romullus]

You're welcome!