UDIMS and Unity.... Aaarrghhh

[Steeve89]

Hello everyone,

I really need the advice of experts and urgently ask for help. The following problem: I have modeled a mesh object in Blender, which consists of about 50 different individual parts. Since I could no longer bear to create a single UV map for each object and assign a material to it, I started working with UDIMs and created a UDIM.

However, after successfully importing it into Substance Painter and texturing it, I realized that when I exported it, I didn't get one big UDIM, but what felt like 200 different texture maps, and I couldn't possibly assign them all to a particular material in Unity. Apparently Unity doesn't support UDIMs at all?!, which I unfortunately wrongly assumed.

I wonder what I'm doing wrong? Creating a separate UV map for each individual object can't be the solution, especially if several objects share the same material? The problem is also that if I add the UVs of several objects to one UV map, I get problems with the texel density and the model doesn't look very coherent in the end.

I'm pretty frustrated right now, and I apologize for that, as I haven't been working with Substance and Unity for that long.

[Cyril Dellenbach]

Hi Steeve,

Thank you for reaching out.

UDIMs (or UV Tiles) are indeed distinct UV sets and if the software doesn't support UDIM worfklow, you'll have to plug each maps for each part of the model manually, which is clearly not the right solution when you have 200 texture maps. 

Hopefully, with Substance 3D Painter you can edit the UVs hierarchy by reimporting the 3D mesh and it shouldn't alter the already existing texturing. I advise you to apply in Blender a single material on the entire 3D model (to get a single Texture Set), but spread the UV islands on several UDIM to keep a decent Texel Density.

Following this workflow, you'll have only a few maps to plug manually inside Unity.

Regards,