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View Full Version : .obj import is stacking uv's into ONE Texture Map



miguel446
11-25-2003, 03:50 PM
All of my wonderful UV's (50 or so) are being placedinto one UV map named OBJ_UVTextureMap. They seem to be holding dimensional integrity but what a pain to have to sort out what maps belong and what maps don't.

Is this the way Lightwave is supposed to be handling this issue?

Michael

jasonwestmas
11-30-2003, 12:58 AM
I've been dealing with OBJ imports and UV's between 3DS Max, ZBrush and Lightwave so I might be able to help. Where did you make your UV texture map?

miguel446
11-30-2003, 06:39 AM
All of my rigging, modeling and UV's were generated in Maya 5.0.

m

jasonwestmas
11-30-2003, 04:18 PM
Actually, it dawned on me what your problem is. I think When you export a model all the UV's will in fact merge into one UV Map. All the coordinates should be the same as in maya. I'm going to check it out and try to do what I think you did. I'll tell you the results later.

jasonwestmas
11-30-2003, 05:21 PM
If I'm understanding how you mapped your object, I know that when you apply different UV maps to the same model, the UV maps retain their own mapping channel which enables you to apply a different bitmap image to each group that you UV mapped separately. When you export the model the UV maps that you made as separate become merged and become a part of the same UV map. So when you observe the UV edit view you see all your separte maps now on top of each other.

When exporting I see no way around this other than to make all your UV map groupings on the same UV map in Maya, export it in OBJ then in Lightwave reselect the UV's in the UV texture edit view and make a new map for each texture group again so that each group has it's own texture map channel again. Your UV texture groupings should be exactly the same when they are on the same map, just make sure they aren't overlapping before you export from Maya. There is a UV editor in Maya isn't there? Let me know if you need clarification.

miguel446
12-01-2003, 08:49 AM
Jason,

Thanks for your input and testing. My research on the matter has resulted in the same findings as you. The .obj format does indeed merge uv's into one map. Although, it DOES retain the same coordinates allowing for use of the UV in whatever program you choose. The only pain (& it really isn't a pain if you only have a few maps) is doing a select by surface in your target app and copying the stacked uv's to new maps. In my case it's a struggle because there are sooo many (every texture on the humanoid characters are UV'd). I have some friends who use this workflow on a regualr basis (ltw to maya to ltw), but they couldn't really help me as they wrote their own specialized software to tackle the issue.

If I knew more about script writing I could theoretically write a script that would select and save various parts from Maya based on UV coordinates as seperate objects. Then I could write another script that would open each individual part and reassemble/name them in Lightwave. I was using this process manually to great success, but realized it was faster to simply copy the stacked maps to new, seperate maps in Lightwave. It took a lot more thought to do but a lot less time.

Thanks for your input on this subject, I hope that it helps others as they come to deal with the issue.