Baking high to low with UDIMS

IAN2

Hi there, how do i bake high to low poly when i have multiple UDIM Tiles?

My low and high poly fbx all have the mesh named correctly with _low and _high and Marmoset recognizes them too, but when i press bake nothing happens, atleast not in the viewport, the bake output psd all have the uv's overlapping, which is not what i want.

Each udim tile has their own material assigned to it, 1001-1005, it works perfectly fine in substance painter and blender, but substance does not have the paintable bake cage like marmoset.

Please help me out here.

Thank you!

EarthQuake

Toolbag does not currently support UDIM baking, however, there is a workaround:

1. For each UDIM, apply a unique material. Name the material the same as the UDIM region, ie: 1001, 1002, 1003
2. Make a copy of the low poly mesh in your 3D software, for each UDIM offset the UVs so they are in the 0-1 range (Toolbag will not recognize UVs outside of 0-1 for baking).
3. Enable Multiple Texture Sets in the baker
4. Bake!

This will give you UDIM-style maps. You won't be able to manipulate them as a single material in Toolbag, but they'll load as expected in other apps.

EarthQuake

See also:
https://polycount.com/discussion/213276/baking-udims-in-marmoset

Sidney Eliot

If one wants to pack UV shells from the same object across multiple UDIM tiles, then one has to apply multiple materials to that one object and assign the corresponding faces to the materials.

This is thankfully quite easy in Blender:

1. Select all objects and enter edit mode (make sure UV sync selection is on)
2. Roughly box select a UDIM tile and select the rest with Ctrl + L
3. Assing selected shells to the corresponding material

Repeat this for every UDIM tile.