Blender-Xatlas v0.0.6 Lightmap Unwrapping and Packing

Hi all,


  • Added a Linux Build (Tested on Ubuntu)
  • Added 64-bit Windows build
  • Added an an Atlas Layout option for UDIM
  • Added an option to pack your current UV’s (may be buggy as I attempt to triangulate then restore the original faces)

None of the current unwrapping/packing solutions were giving me what I needed for my lightmaps so I looked at integrating Xatlas as an addon.

Blender-Xatlas is incredibly hacked together but I’ve gotten good use out of it, compared to other unwrapping/packing methods when it comes to lightmaps.
Any feedback is really appreciated, I’d like to bring it up to an acceptable standard.

Make sure to try it on a small disposable scene first to get a feel for it!


Default settings for 1024px lightmap (no realtime lighting)

Standard Pack/Xatlas Pack(Note: attempts to maintain relative UV scales)

You can get the latest Windows/Linux version from:
Blender Xatlas Github



Looks like Xatlas make an auto-seams when seams aren’t manually provided? But how much stretched the islands turn out? Packing aside, it gives acceptable results with props/vehicles like assets?

Yes, it unwraps the meshes. Xatlas itself can pack your manual uvs but I haven’t added the option in Blender-Xatlas yet. With basic settings stretching should be limited.

For lightmaps I think it gives acceptable results, definitely better than any other form of automatic unwrapping I’ve found.

I’ll work on making more examples, but here’s a quick one:

It’s great that you have implemented xatlas in Blender. Certainly shows some significant improvements over things like SmartUV on some of my models.

Unfortunately it fails on many of my models. They are imported from Revit, so the meshes are quite messy, but SmartUV manages them (slowly).

I realise you may not be working on this any more, but if you are then perhaps I could send you a sample model so you could see what is going wrong? It isn’t your problem, so no reason why you should, but if interested then I would be happy to share.

I’d be happy to look at it.
There’s a few areas I could see failing, I just never came across them myself!
Anything that improves it is always appreciated.