Warping 2d graphics with 3d reference

Question

This is my first foray into the 3d realm and I'm trying to use a 3d scan from a Kinect imported into photoshop as a template to warp grapics or image files so they can be realistially applied to a 2d photo of the same item (I've been able to import obj, stl, or dae files so far).
So far the hang up is with editing the texture. When I try to edit the diffuse texture so I can paste in the 2d graphics image to overlay and conform to the 3d layer it brings up texture file with a mesh that is broken down into sections which are arranged by size across the canvas.
Is there a way to convert these imported 3d files so the texture mesh isn't broken up? Otherwise, when I try to put a pasted graphic over the mesh in the texture file it just gets cut off at the place where that section ends when I look at the result on the main file. Is there a way to get it to handle more like the kind of 3d file you make when you convert a 2d file to a depth map or is there any other route to my intended result?
Many Thanks for any help with this!

Answer 1

When you edit a texture from a 3d object and you see black lines drawn across the image, those lines represent UV borders. Photoshop lacks a way to edit those borders. But other 3d programs can and there are 3rd party programs specificly design just to edit UV maps.
For an example:
If you had a box with 6 sides and it was properly uv mapped (so that it makes sense to humans) You would see a line for each edge of that box inbetween those lines is where you would place an image. Some would be scaled, others rotated or both.
When done, that single texture would contain textures for each side of that box.
But computers don't need lines to be straight or evenly spaced for it to make sense to it. So some UV maps look like spegetti or a jumbled up mess.
A mesh does not need to be UV mapped though, it can have a single texture for each side of that box, but when multiple sides share the same texture(image) it makes sense to combine them into a single texture(file).
From what I can tell photoshop also lacks the ability to select a side and give it a new texture. I could be over looking it, but I have a feeling that we need to wait for an update that does include it.
Until then, another program will need to be used to either create proper uv maps, or to assign polygons a surface name and give it a texture.