PS CS4 3D Painting troubles!

Question

I work frequently with SketchUP Pro and can export in a variety of formats. When I export a .obj file and bring the model into PS as a new 3D layer, I find that I canNOT figure out how to actually paint on the model itself. I've tried a bundle of different ways, read through tutorials, watched videos and none of them seem to tell me exactly how to do it.
I've got a brand new mac pro - with ati radeon hd 2600 (openGL 2.0 supported), so I should absolutely be able to do this. Any ideas or foolproof methods of being able to paint directly on a 3D model in PS cs4?
Hugely appreciated!!

Answer 1

Isolating 3D parts is a selection process. You select the polygons you see, expand/ contract from there, then hide the layers/ polygons you don't need. In both your examples it seems that neither of you has a proper contiguous UV set in the files, so any painting will fail because your UV data only contains isolated islands, giving the scatter. And a very knowledgeable 3D developer once told me, that the Sketchup OBJ files are the most atrocious and out of whack ones on the planet, so this certainly adds to the problem. In any case, you problems can only be solved by going back to your 3D programs and looking for the right options. If you have no access to a 3D tool yourselves, I recommend downloading the free blender. This would at least help to verify the defunct nature of the UV sets and after a little reading up and practice you may even be able to create your own UV sets, e.g. based on a cylindrical projection for the bottle. I also recommend you ignore realworld scales when exporting your models and instead make them large-ish (10 or 100 times the size). This helps circumvent the OBJ format's precision issues and will improve handling, as PS will equate 1 unit to 1 pixels and the more units/ pixels you have, the more precise the handling.
Mylenium