Hi all, I have a very odd problem with UV maps that no one else online seems to be experiencing, and I am totally lost.
I made an object with UDIM UV maps that I then exported to Substance painter and painted. As far as I can tell I imported those same maps, but it seems Painter is changing something with the UVs, because when I then export those textures back to Blender and apply them the parts no longer line up. Even when I export the mesh from Painter and apply the texture I get the same error, so it appears to be keeping the original UVs in some form. I honestly cannot figure out what is going on.
But then when textures are applied to that exact same object they are misaligned (ignore the other textures, just focused on the hull with all the black shiny gaps):
Clearly Substance Painter and Blender are reading different UV maps, but I canāt figure out how and why Painter is changing the map, and how to realign them. As I mentioned even if I export the mesh from Painter and bring it into a new Blender file it still reads the original UVs.
Can you share Just a Small section of this modelā¦Iāll see what the problem may beā¦
Share your export workflowā¦from both as well as Import workflowā¦
Thanks so much. I really need some help, I canāt even find people with similar issues.
Iāve since tried the whole process again: unwrapped in Blender with auto unwrap, packed UVs with Packmaster, exported as FBX (and also tried as obj), and I have tried applying bevel modifiers, not applying, applying and reunwrapping, every combination.
I import to substance painter using UDIM workflow, no autounwrap in substance, I bake meshes in substance and then it textures fine there, but exporting either the textures and adding to the blender file, or exporting the mesh from sp and then trying to add the textures in a new blend file gives the same result.
Here is the blend file and the udim colour tiles for the hull material:
Iām pretty confident the problem is in sp though, where it seems to be just slightly changing the UV layout. I can share that too if it helps but itās a massive file
Yes I did without any auto unwrap, when it didnāt work I also tried the re-import option with āpreserve stroke positionsā which didnāt seem to make any difference. What doesnāt make sense to me is that the object textures correctly in substance painter but even when I export that mesh and import it to a blend file it uses the orginal UVs and ends up a mess. Like, shouldnāt it at least be using the new UV maps sp appears to be creating?
OKā¦Iāll take a look at these (it may take a while) and I must say, I have an older version of SP, (I refuse to go subscription on something I rarely use ā¦)
( Thunderstorm also just hit and knocked out power soā¦wait time may be a bit longerā¦
Thank you! I just recently subscribed after trying Quixel Mixer which kept crashing and was very slow, so itās been pretty frustrating to now have problems with this too haha
Yeppā¦ after adding a texture settup with set to udim (and once refreshing so all tiles would be loaded) and copying it to almost every single materal (some maybe still wrongā¦??):
Thanks for trying but thatās still wrong. Those maps are only meant for the hull but you can see the textures arenāt aligning, check the doors of the legs and the front panels where thereās a bunch of random shapes. If you looked at the UVs over the image texture youād be able to see itās not aligned. Those big brown patches shouldnāt be there
Interesting. Iām right now in the exact same work flow - spaceship, unwrapped to uv udims, exported as fbx, imported to painter and started texturing. However, thatās how far Iāve got in the process and itās my first time using this workflow, so I may be the wrong person to look over this.
When I open your blend file, I see a lot of overlapping uv islands. Isnāt this going to cause some kind of problem?
I dont believe so as those overlaps are different materials, thereās no overlap within a single material - but for what itās worth, the original red one had zero overlaps even across materials. I am new to UDIM workflow too and I think the way Ive got it now is correct, but either way I was still getting these issues even when I had it unwrapped across eight or so tiles.
The only thing I can conclude is that there is something wrong with the mesh and when it gets triangulated and sent into SP thatās causing an issue. It would surprise me if having ngons would cause that but there are parts that work fine (eg the cylinder ābatteryā objects).
I am feeling like I just have to give up but I really dont want to start a whole new project and encounter this again when I come to texturing D;
Hmmā¦Iām not 100% sure how it should look like, but when I load your textures into an image texture node set to tiled (udim) and connect it to the color input, I get this and it doesnāt have the light/grey parts on the gear door as seen in Okidokiās picture.
I did just do a quick look in your file:
Wellā¦ the problem might be that the red Hull material with the texture FIXED UDIM small ship_TEMP HULL_BaseColor.1001.png has to be connected with your small ship againagainagan_Hull_BaseColor.1001.png file set to UDIM and reloaded and then also for a lot of other materialsā¦ but i donāt know how your workflow in this and didn;t looked at ever UVmap which seem to no use this textureā¦ so having a look at this file is not so clear or simple as you might thinkā¦
Just using this hull material an doing the UDIM setup as @gorion103 originally suggested and checking again what @WK042 postedā¦ i just thought is was okay but blender seem to not have updated the UDIM the irst time correctlyā¦ now just using the hull material it look like thisā¦
Why is there no connected texture anyway ?? Those things are the HULL material on the working panels (yes not Hull)ā¦ and there the textures are Single Image not UDIMā¦ ( ā so this is you problem ) ā¦
(you canāt expect someone to know whatās going on by just looking into that kind of fileā¦ itās somekind of info overflowā¦ maybe a simpified file would be the better choice to discuss this)ā¦
According to triangulation and n-gonsā¦ as far as i know SP donāt like that to muchā¦
AFAIK the big trick of UDIMs is no overlapping UVs and only one material (besides using different sizes on every tile)ā¦
ā¦because then you could have used just different materials with different shadersand different sizes of UVmaps anywayā¦ ( ā so this is also adding up to you problem ??) so the big deal is no material switchingā¦ everthing is on one shadersetup and one big UDIM space (expect albedo, metallic, normal, ao)ā¦ so only three windows: model, shader, textures (maybe four for the texture typesā¦)
YES! Thatās done it! Thank you thank you thank you, I owe you a beer. You have solved hours of grief, and now I donāt have to abandon this project. I really appreciate the help!
) ā¦