SoftImage not saving 2nd UV for lightmap in obj?

Desperad0

I thought it was ZBrush, but after remaking the second UV set again I realized it was disappeared when I export the mesh as .obj. How can I export a second UV set for lightmap painting from SoftImage, and have the file be paint-able in Mari? Does Mari support fbx?

WarrenM

I'm not sure about the rest of your questions but I can tell you that the OBJ file format only supports 1 set of UVs, so that's why it isn't working.

Desperad0

Sorry if I'm not making sense. I want paint texture and lightmap for a mesh in Mari, but Mari seems to only support obj, which only saves 1 UV set (which has overlaps). Does that mean:

1. have 1 UV set on .obj in Softimage
2. paint texture in Mari
3. import that .obj back into Softimage
4. create 2nd UV set for lightmap in Softimage
5. take 2 UV to Photoshop and paint the black and white lightmap
6. put the lightmap .tif back into Softimage
7. connect everything, and export as .fbx for UDK

Is there a shorter way?

If I do not overlap anything, and shrint the UV down, won't that make the texture blurry and low res (and ugly)?

WarrenM

Does SoftImage not export to FBX? That would be your best bet I think. I don't know Softimage or Mari really so I can't really help in those areas.

As for the lightmap UV, yes, you have to have everything unique and not overlapping. Lightmaps are inherently low res anyway so blurriness isn't generally a huge problem.

Desperad0

What about shifting the second uv set over to adjacent cell, then merging UV set 1 and set 2 so the cells sit next to each other? Is there a way to do that?

WarrenM

I don't think so. That would be double UVs on all of the polygons and I don't think most programs support that.

Desperad0

I see... so probably best to stick to 1 UV, texture everything, and then when all that's done, take the obj into Softimage to make 2nd UV for lightmap, then Photoshop paint that. Then export fbx. Wow!

WarrenM

Or you could switch to a modeling package that supports modern file formats. Just sayin'. :P

Desperad0

If you pay for them for me, gladly! (I only get access to these super 3D programs until mid August when grad school ends, so I'm trying to eat as much as I can in this knowledge buffet)

cryrid

Or you could switch to a modeling package that supports modern file formats. Just sayin'. :P

Softimage supports FBX. You can even use the latest version of Crosswalk (2014?) even if you're still using an older version of Softimage itself (like 2011).

Multiple UV channels should also work fine with FBX, assuming you're not on a significantly older version of Crosswalk. Years ago there was an issue with second UV sets, but AFAIK it's been fixed for several versions now.


The steps you're taking are a bit confusing, especially when comparing the information on the first post to the next. As mentioned, OBJ only supports one UV set. So if you're exporting to something like zbrush, mari, or even photoshop then you'll want to work on a cloned model that only has one UV channel (the one that you wish to use). Delete the rest before exporting that OBJ. Once you're ready to export the model with every UV set to UDK, GATOR should let you transfer the various UV channels to a single mesh before exporting to fbx. There may have been a time (4+ years ago?) when you had to set up a material that would use each uv channel before exporting the fbx, but I'm not sure if that's still the case (I doubt it, but try it just in case).

WarrenM

Google has failed me, cyrid. What is GATOR?

Ark

GATOR is a XSI specific tool, allowing you to transfer attributes between models.

WarrenM

Ahh bummer. Thanks!

Desperad0

Man we had that 1 lecture on GATOR so long ago I clean forgot it even exists... or how to use it at all. I'll go dig out that lecture note and recorded lecture on GATOR. Thanks! I wish I can still use Softimage after leaving school, it's got some really nice tools like ICE and GATOR, but it seems to be even more expensive than Maya. Thank you guys!