how can i bake a multi image UV-texture ?


I got a problem with creating a UV texture for a complex object. For simplicity
let me explain my problem on a simple cube:

Assume, the cube has been UV-unwrapped and the uv-map exists already, containing 6 square faces.

Now I select one face only, then in the UV-image editor i open an image (image1) and map it to the selected face.
I do the same thing 5 more times, but for each UV face of the cube i open a different image (image2 - image6).

When now looking at the cube using draw type “textured” i can see my 6 images nicely placed on the 6 cube sides, where i expect them to be. That’s fine.

Now in the final step i want to create a baled texture, that contains all my 6 images with each face-to-image-mapping preserved. So i can use the final result as one single texture-file for the whole cube. Isnt that part of what texture baking is about ?

But whenever i try to do it (using render -> bake -> textures only), i always end up with a black cube,
and all my input images get overwritten with black…

As soon as i click on image -> reload, the original images reappear on the cube at the correct places…
I get something, when i use map input and multiple UV-maps, but this doesn’t allow me to use multiple images,
or at least i havent figured out, how that should be done. So… what am i doing wrong ???

I know, i could do this mapping manually in an external paint program, just export the UV-map, place the images at the correct places and thats it. But i want to do it in blender…
I would bet, that it is possible to render such a composite texture with blender…

I also played with the node editor, and maybe i have to use several UVmaps at the end, one for each face of the cube ? But i simply am now at the end of my phantasy. And i am almost sure, the solution is simple (as always :wink:

So, anyone can help me here ?

thanks a lot

Okay, not simple, but simple, if you follow these steps.

  1. set each uv unwrap as a separate vert group with it’s own material in, but still the same UV Tex layer
  2. For each new material, add a texture, image type, and load the corresponding image and set to map to UV and name te UV layer (default is UVTex)
  3. Once each vert group is finished and the images that you uv mapped are loaded to the corresponding vert groups’ material, you can then go to the uv image editor header and click ‘image’
  4. choose the top python script ‘consolidate into one image’ and then watch it bake the images into one uv map, though the scales of each uv unwrap will correspond to how you set the scale in realtion to each individual image.
  5. save the new image and you should have what you are after.

There might be some questions, but I ripped through this because I always wanted to know the same thing. :slight_smile:



After working with this example a little longer, I renamed the consolidated image and attempted to map it directly in the material.

The main thing I found was that I needed to go back and deleted the original materials and vert groups without eliminating the UV Layer name. I set up a new material and added the consolidated texture image as a new texture mapped to the same UV Layer name, and then it showed up mapped correctly. I guess because the vert groups were present, it was still looking for the materials that had been associated with them. Possibly might be a good idea to duplicate the whole object before consolidation so as to have a back up if it goes wrong.

That video may help, he does texture baking in the video.