Blender and baking multiple materials on a single object

Hi, I wish to know of a better way to add multiple materials on a single object in regard to baking using cycles.

With my gun please see image, I wished to have three materials on this single object and bake the materials to the texture image.

I found I could not bake the materials with them all assigned to the model.

The model is uv mapped, but I wished to have all of the materials baked on to the model.

What I did was to select the areas of the model, Separate them assign the chosen material and bake each one in turn.

Remembering to save each baked image I rejoined the separate pieces back together

The model now has the three materials slots referencing the baked images.

I am thinking I could merge all of the saved images onto one single image texture and just use one material.

Possibly there is a better way to bake separate materials than this way?

Thank you for you time to read and advice.


I think this is where I am at with this. I too am trying to add two materials as one. You- 3 into 1.
I think you need to send it over to 3rd party like P.S or Gimp all three layers merge and polish, export as on PNG to UV unwrap and assign as desired.
I am wanting the same thing, but I also want a bump map that reacts to light in my 3rd party export/import of texture. To be light weight for animation. Trying to avoid geo Not sure how to do this yet, for texture. Going surfing for clues now…

So you saved each bake as a layer then merge them in P.S Check out this vid at about 17:00 of the second vid of the two part series.

For your bump mapping you could use the Gimp plugin for normal mapping

I use Bitmap2material

When it comes to merging images I use

Thank you for your time