Mesh export stacks UVs - any remedy?
sofax
Posts: 37
No matter what I try, I can no longer export OBJ files (or any other format) with the UVs NOT stacked on top of each other - which makes the OBJ useless for my purpose of importing it into another program for painting.
This has always worked until a couple of weeks ago. Has Daz Studio been modified, and is this intended behavior or a regression?
... and how can I "unstack" the UVs?
Post edited by sofax on
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As long as the surfaces are assigned to different material zones this is not a problem.
It apparently is with Mudbox. I can't use the stacked UVs from the exported OBJ - they will not be mapped correctly. It used to work fine until a couple of weeks ago.
Perhaps I'm doing something wrong, but I have no idea how to fix that.
I guess with Substance Painter it might be possible to work around this problem, but Painter can't paint across UV tiles, which makes it a pain to use when painting Genesis characters.
However, I'm still pretty new to this all, so I might be missing something. Old brain ... ;)
Except for the Genesis 8s (maybe some other newer models) that use UDIM UV mapping most all the models here have stacked UVs.
I'm afraid, that doesn't help my case. :/
I found out that FBX export does not stack the OBJ (anymore?). However, the FBX UV layout is different; the textures are split into 16 tiles there. E.g. the original UV set contains the face, the lips and the ears in one single tile, whereas in the exported FBX those three textures are split into three UV tiles (1001, 2001 and 5001).
While it is feasible to use that for painting/modifications and then combine the resulting files in GIMP or PhotoShop according to the original Genesis UV set layout, it's an extremely tedious and ugly workaround.
Thanks for the video, @Ascania - it just popped up now, so I did not see it before my latest post.
However, I don't see how that video could help me. I want to work on existing textures that I've created for the Genesis 8 Male using the standard Base UV set. So both the input and (definitely) the output should be a set of textures conforming to that UV set.
I know I could probably use the UV map transfer utility in DS to convert the FBX UV layout back to the standard G8M layout, but this tedious and VERY time-consuming work would not be necessary at all if the OBJ export had (at least) an option to avoid the stacking of the tiles.
is there a way to hide the layer you not working on?
for example, in carrara there's a tick box for show all, or select only the layer you want to work on
To clarify again, as I think this wasn't quite clear before: I want to import existing texture sets using the G8M standard UV set layout into Mudbox, work some more on them and then export the final texture sets from Mudbox for use in Daz Studio again.
Right now I have to duplicate and rename my original texture set files to match the tiles from the FBX export in order to be able to import them into Mudbox (or import them one by one and make sure I click on the correct file names), and after the paint job is done and the files have been exported, I have to do the reverse procedure.
If the OBJ export still worked as before, when it did not stack the UV tiles, none if that would be necessary (and I would not have to use FBX as a workaround either).
ds has that lovely uv camera. but no way to export it as a template.
Yes, that's common in all 2D and 3D paint programs I know. But how does that relate to my problem? :)
thought you were trying to paint on a layer?
Nope, that's no problem at all. It's about the file formats/UV sets and how to get them in and out of Mudbox (or other 3D paint programs, too) as desired. The Genesis 8 Male uses a UV set by default that has the ears, the lips and the rest of the face in the first uv tile (1001), the torso in the second (2001), the legs in the third, and so on. That's what my existing textures are set up like.
The way OBJ export in Daz Studio used to work, the UV tiles stored in the exported OBJ were not stacked. I would, for example, name the texture set that contains the face, lips and ears something like "my_character_u2_v1.png", and Mudbox would import it correctly. Now that the UV tiles in the exported OBJ are stacked, Mudbox won't map those textures correctly anymore, so I have to use FBX as a workaround - where I have to deal with way more texture files due to the different layout. And then finally I have to convert (merge) the files back into the G8M standard format. I would like to avoid that.
sounds terribly complex
i find it easiest to use an existing texture map as a guide.
create layer over it in photoshop and paint on the layer.
Is this what you are looking for? Apologies if I misunderstood yout question.File/Export when the dialog box comes up untick Collapse UV Tiles.
@DestinysGarden: Yes, that's what I'm doing. When I export my G8M character as an OBJ like that, the UV tiles are stacked... and that's new behavior.
OK, figured I try for the hopefully easy solution. I'd put in a support ticket then. I'm not aware of any export behaviour change, but I always need my UVs stacked for the paint program I use to texture.Checking or unchecking that box should still work, and if it doesn't, I'd report it as a bug. Best of luck.
I use GIMP for "post pro", but when I work on the initial maps (especially the albedo map), I use Mudbox or Substance Painter (which I have only been working with for a couple of days, actually). Painting on the flat maps in a 2D painting program would be too difficult. Besides, I like to use photo references for projection instead of hand painting the whole character.
I'm afraid this new behavior might be intended - for whatever reason. Perhaps someone from Daz is reading this and can shed some light ...
I have an older version of my mesh that I exported roundabout 2 months ago, and that OBJ is "correct", i.e. the UV tiles are not stacked.
are you talking about painting across seams?
sorry for being obtuse.
Painting across seams is an issue, and so is judging from a plain 2D view what the result will look like when projected on the 3D model. And it's impossible to match the 2D view to a precise position of a detail in the 3D mesh.
there are modeling programs that let a polygon color be assigned to a single poly or select polies to export on the uv template. It's one way to make a make-up texture template. color in the eye liner or lip liner. put a beauty mark in the right place. wings3d v99.5 had the feature. think later versions removed the feature.
Are you by any chance forgetting to delete the eyelashes?
also collapse UV tiles needs to be unchecked for UDIM
No, I'm only exporting the plain character. No eyelashes, no eyebrows. My settings are exactly the same as in the screenshot @DestinysGarden posted. I tried different settings, too, just to see if it makes any difference.
Are you sure you haven't somehow updated the mesh (by yourself or through a product) so that it is loading with collasped UVs? Have you tried Genesis 8 Female, or one of the Genesis 3 figures? Do they have the same issue?
I have not tried G8F or G8M itself - that's a good idea, I'll try that tomorrow.
I did not change the mesh knowingly, but you never know ...
Absolutely nothing has changed with the wavefront export. With the Genesis 8s you need to check Collapse UV Tiles otherwise you get UDIM tiled UV mapping. You say you have just started with Mudbox and Substance Painter so the problem may be in the programs. I have just imported G8M in to Blender and everything works like it always has.
It does indeed work with the base Genesis characters, so there must be something wrong with my morph. I'll have to fix an error in the mesh anyway, so what I'll do now is:
1. Import the OBJ with the stacked UVs into Mudbox
2. Import the UVs from the original G8M and then re-export the result as OBJ from Mudbox, overwriting the broken version (i.e. the one with the stacked UVs). That will fix the UV problem.
3. Import that new OBJ into Blender and fix the little mesh error there
4. Export the OBJ from Blender
5. Import the OBJ exported from Blender using the Head Split DFormer to recreate the head and body morphs in Daz Studio
Step 5 is not necessary for the texturing job, of course, but to fix the character morph.
Thanks for listening, everybody! :)
Unless your morph is ERC linked to the UV set, which would be tricky to set up, I'm not at all sure how a morph could affect the UVs. Have you created a new figure asset, rather than using morphs for the base figure?
I found the cause - even though I still don't quite understand it: I had my own UV set applied to the character, but that UV set is an exact copy of the original G8M UV set. I just set it up that way in case I'd want to change anything to the layout throughout the development process, but I never actually did.
Anyway, after resetting it all the the original G8M UV set, the issue is resolved (for now).