Change Material based on Camera (TextureRenderTraget2D)

I have multiple cameras (TextureRenderTargets) in my game. All of them get rendered at the same time.

I know I can use different Post Process effects on these render targets, but that’s not what I want.

Is it possible to react inside the material for a given render target ?
Is there some variable / parameter I can access inside the material functions to change rendering behavior ?