Combine materials to single material

Introduction: I believe this would not be too complex thing to do, but still useful, so thats why I dare to request it.

Let's say you have a model of a robot that has different material for its head and body. Now, because of some reason, you need the model as a static mesh and you would like to merge the head and body to single object. Let's say you for example work with a project where you need "dead robots", so you also want to have some sort of a global effects to the robot materials to represent that they were burned. For that it would speed up the process very much if all the materials assigned to the robot were single material instead.

Alternatively, you would maybe want to bake all the textures very fast.

Feature request: My feature request is a process where the materials could be combined together as a single material.

What it would do: First it would group all the material nodes inside the material to be their own groups.

1. Head material group
2. Body material group

Secondly, it would greate a vertex color map for each of those materials, or if we somehow can hack face maps or some other mesh data to be used in cycles, then maybe those.

Basically it would create a mask of the area where each of the materials used to be, and would be painted white.

Lastly, it would collect all of those groups into the "combined material" and use the generated masks to mix the groups together to create one single material that looks exactly how the object was with multiple materials.

If this somehow could be done nondestructively, it would be even better. With "nondestructively" I mean, that we need to somehow only deactivate the old materials and be able to come back to them if something goes wrong.

How it would be used: You should be able to in material panel be able to shift select multiple materials and select "combine materials".