Combining UV's with different objects
So my question is on if this is doable. But What I need to do Is combine the UV's of 2 different objects. Meaning that at the end they will share the same UV map and a single texture will be good for both of them. I have 2 models that each have there own UV set ups they also both have great looking texture, normal, and specular maps, which I do not want to re-bake or redo. Is there some way that I could simultaneously move the UV location as well as the actual picture areas in the 3 maps.
Yes I know I can move pictures in Photoshop but I need a quicker way.
Yes I know I can move pictures in Photoshop but I need a quicker way.
Replies
That's not really helping me, How will I move the locations of the texture maps I already have to match the new UV locations.
You should create a new UV channel (UV 2 for example) that contains both objects. Then bake each map from UV1 into UV2.
Baking the normal map is more difficult, because UV rotations will require different gradients. Best thing is to re-bake from the high-res models.
You need to apply the normal map as a normal map, making the UV 1 model look like it's a high poly model.
I've never tried it in the case of re-baking, but I've used normal maps on high poly meshes to add additional detail in the past, and it baked into the final normal map texture just as if I'd used geometry there. Might be worth a try.
Failing that, if you keep the orientation and shapes of the UV Islands the same and just rescale and move them then the normals should still work if baked directly.
As Eric and passerby have said, baking the other maps should be just a 1 to 1 on the UV's, occluding or intersecting geometry shouldn't make a difference to the bake (it will make a difference when re-baking the normals though).
You may get random pixels in the normal map bake, at least I did when I did this. If so here are a couple solutions, plus an example pic...
http://wiki.polycount.net/NormalMap#Solving_Pixel_Artifacts
I'm not really "back" so much as popping in. I am going to make an effort to pop in more often though, since the last time was almost 5 years ago (eek).
VisceralD, what Eric said.
Just combined the two (what I assume are square) textures side by side into a new 2:1 texture. Offset the UV's of the model to the left texture by 1, scale all by 50%, move right by 0.5... done. Don't have to rebake anything, can still use source .psd's by textures... but only if your engine supports 2:1
The offset trick is a good one though, no UV fiddling, no rebaking. Much better! Rebaking maps is a bit of a lossy operation, re-rendering will filter your maps, adding some blurriness. Also the offset keeps all your layers intact!
edit: this is what I mean
If your original textures are both 2:1 you could combine to one square UV (assuming they're the same resolution). If they're some odd combination then you'll have some wasted space that another asset could possibly use, but that's still a bit fiddly.