Bake image from Mix Shader node output to show BSDF base color without light gradients

Question

I've a shading node setup to create a scratched surface, to show wear of paint. I'm using Blender 2.80. See the image below.

I would like to export the model to SteamVR, and for that I need a single diffuse texture (normal map can be set separately in the SteamVR model). I was hoping I could bake the result. The baked result should not contain shadows or light gradients or anything, only the base color from the BSDF shader, combined with the image from the mix shader so show the scratches. So I expect no gradients, but a homogenous surface color, with scratches here and there, (showing through the other picture of wood). See the shader node setup below.

Shader nodes:

Bake setup:

I tried combining different options. But none give me the result I am looking for.

Result:

This is the best result I got so far. It shows the base color (white) with the colors of the wood texture (to show the scracthes). But the base color has gradients, which I do not want. I do not want the darker color on the left, but a homogenous color. How can I achieve this?

Answer 1

I found a way to do it. The only thing that I changed is setting the Emission parameter of the Principled BSDF shader to complete white (it was completely black).

Bake settings:

Result:

Downside:

The color of the texture created is no longer determined by the "Base Color", but by "Emission". So probably any other thing going into the base color parameter wouldn't end up on the texture I am affraid. But for my use case, this setup is giving me what I want.

Answer 2

Although I do not know how to do this in vanilla blender, I highly recommend the Principled Baker add-on.

With this add-on you can bake (almost) any complex material into multiple texture maps (color, metallic, roughness, normal, etc.) to feed into one single principled shader, and the render result should be identical to your original node setup. The color map is unaffected by lighting, and works on both metallic and non-metallic surfaces (unlike the vanilla diffuse baking), which should meet your need.

When you have the add-on installed, select the object(s) which you want to bake, go to the node editor view, and press N to bring up the Principled Baker panel. Either use the auto detection mode or manually choose whichever maps you want. It will automatically export all the maps you have selected at once.