Photoshop Extended 3D OBJ file

Question

I created a model in a 3D package and imported the .obj file into Photoshop Extended (CS4).  I painted on the model in Photoshop and I was hoping that I would be able to reimport that painted model into the 3D package.  The export options for Export 3D Layer in Photoshop allowed for exporting the texture (a dialog came up) and I chose TIFF.  But when I looked in the textures in the 3D package I just saw a simple texture without any of my "painting" on it, in other words there were no links to Texture Placement icons or anything of that sort.  I just got a basic gray texture which was incidentally the same thing I imported into Photoshop, just a different name.
How can I export the painted portion of the texture into the 3D package?  Am I supposed to save the file as a PSD file and then import the PSD into the 3D packages texture attributes section?  Any help is greatly appreciated.

Answer 1

Thanks Mylenium.  I looked into the 3D pkg help files and it had a literal blip on MTL files which said that they only work in certain instances.  Turns out that the MTL doesn't work at all (at least not with the method that I tried--but there's no explicit help on how to use it either).  However if I save the texture material as a TIF and import the TIF onto the surface then it works perfectly.  I probably could use other popular image formats as well that Photoshop offers when exporting the OBJ layer.  But you definitely pointed me in the right direction by having me look for an MTL file.  Great!!