simulating machining with normal or bump maps

hi,
does anyone know how to simulate machining process using normal or bump maps? (i suppose this approach could be easier than destructible meshes)
i just dont know how to create these maps evolving over time and having control over its size (or geometry) when it is being developed.
any help would be greatly appreciated
BR

I don’t think that would work, but you could probably do that with Morph targets

Look at tutorials for Snow Deforming, Material Deforming, etc.