Multi-pass vertex shaders

I’ve searched extensively to find an answer to this question but I couldn’t find an example anywhere. The shader documentation isn’t too elaborate and I couldn’t really find an answer by going through shader code.
What I’m suspecting is that I’m too much in an OpenGL mindset and that things are done differently (and are probably much easier) in UE4.

What I’m trying to achieve is the following:

  • render an object with material A
  • then render the exact same object on top of it with material B and a vertex shader that changes its geometry

I know exactly how to do this in OpenGL but I haven’t got a clue how to do this in UE4.

Any hints would be appreciated.

I found my answer in this question: Are Multipass Blend Texture's going to be suported? - Asset Creation - Unreal Engine Forums
The answer is no. I’ll have to duplicate the mesh manually and apply a material to it.