Fixing some bad UV maps from an imported OBJ

I have an .obj that was exported by someone using Marvelous Designer (MD), and the UVs are a mess. I’m trying to get it re-made and exported without the problems I’m about to describe, but in the meantime I’d like to figure out how to fix it on my end in Blender.

For those not familiar, MD is a cloth simulating program designed to be intuitive from a “tailoring” perspective. For instance, if you need a coat for a character, you would patch it together in MD using the sewing patterns and 2d shapes of a regular coat before simulating the cloth to create the actual object/animation of the coat. In terms of UVs, this can be incredibly handy because the shapes you’re sewing together (just flat pieces of cloth) are exported as the UV map. This removes the need to worry about any UV unwrapping weirdness with complex geometry, wrinkles, etc.

Unfortunately, it’s given me something that I can’t really use effectively. The object I’m working with is composed of about a dozen different shapes, all of which are correct but overlapping (looks like the center of every individual shape is in the exact same spot) when I look at them in Blender’s UV Editing workspace. It’s also enormous. I can’t zoom out far enough to see even a quarter of it all, and when I load a 1k texture onto a material for this object, it looks like a dot at the center of the UV map. I’ve watched several guides on UVs, and aside from making my brain melt a little (this is an area that still makes almost no sense to me beyond the simple concept of the map being 3d shapes stretched on a 2d canvas that can serve as kind of a stencil for texturing), they didn’t give me much to work with. Most of the questions/answers I find here have been more about unwrapping or generating UVs from meshes that don’t have any yet. It’s possible I’m just searching for the wrong terms - any chance someone could point me in the right direction here?

Not sure exactly without seeing the issue, but did you try going into edit mode (with all the pieces combined, you can separate them later I guess), select all, and in the UV editor going into UV - Pack Islands? That should arrange them into 1 single UDIM, non overlapping. You might need to re-arrange them afterwards though.

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Wow, that is exactly what I needed, and such a simple fix. Thank you very much :slight_smile:

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MD has a lot of options for exporting that affect the UV map - you can get quads, tris, and a variety of resolutions. The way the pattern pieces are laid out in MD directly affects the UV layout on export. That said, when I bring something into Blender I’ve made in MD, I usually remap it anyway. Or at least resize and rearrange the pieces, depending on how I’m going to texture it.

It sounds like each island was made to have its own UV map (not a deal breaker as often you can use one texture set for several objects) but if you wanted it all on one texture set you could make a new map, and on the new map you can just select all the meshes, go to UV in the UV editor and pick “pack islands” This way you still have options of baking from one texture set to the other.