Author Topic: Problem with UV Reprojection  (Read 843 times)

Hi

I'm not sure if I've used it correctly, but I can't seem to get the UV Reprojection feature to work correctly. Basically, there was something I forgot to do to my original high and low polys prior to baking - the lid of my loot crate was supposed to be separate to have an open/close animation. I spent a lot of time UV unwrapping, baking, and then painting/texturing everything that I don't want to go back to an earlier save and re-do it all again.
So, I learnt of the UV Reprojection and thought I'd found my saving grace. I did have to import my baked mesh into 3ds Max, add some new edges and detach the lid. All the geometry is in the same place though. I did have to re-do and arrange the UV islands again, mind. However, when I attempted the reprojection, the paint/textures have gone everywhere. :-\

Not sure if I've done the process right or if I've done something wrong.

Anyone? :(

I know how to manually fix it but it involves taking the old version, exporting the textures, and fixing them up to the new UV shells and re-importing. If the UVs are the same size but just moved around you can re-position your textures then import them into your Painter project and apply them as a fill layer. You just need shell masks to make it easier to apply your textures to the moved shells.

I personally don't get good results when attempting to bring changed meshes back into Painter so I don't bother anymore. That being said, I rarely run into this due to workflow checks but in the last year I had two projects I had to go back and fix.

Read up here and take note about:

"
Since every stroke made in the 2D view is performed in the UV space, there is no way to reproject it properly in case the UV of the mesh change dramatically after a reimport. The best way to make your project reprojection proof is to rely on masking by an ID map and other type of selection and painting instead the 3D View.
"

https://docs.substance3d.com/spdoc/uv-reprojection-28737554.html
I teach people how to use Substance Painter. :)

I'm not sure how you would mask by ID type. I have material IDs set up though... For the most part, with the exception of the top, I was painting the 3D view with my screen tablet.

When you say you exported the textures and fixed them up to the new UV shells, were you manually manipulating the textures in Photoshop?

When you say you exported the textures and fixed them up to the new UV shells, were you manually manipulating the textures in Photoshop?

Yes, I have a workflow I use to generate pre and post masks, then I alter the textures per channel as needed outside of Painter and re-import them back in. If your UVs are just moved around or by splitting your objects you have more than one UV map and the shells are moved over it is an easy fix. It becomes more complex if you've unwrapped them in a different way. If they're just split up shells it wont be an issue.
I teach people how to use Substance Painter. :)

Yeah, sadly it's not simple. It never is. :-\ There was something I should have done prior to baking and painting my textures. I should have detached the lid of my loot bin, given it its own material ID and unwrapped it first. Doing that after all the baking/texturing breaks up some of the existing UVs.