This the result: the red reference square seems to be on top of it, but because it's transparant you see that grey square is in the same plane and that the black dot makes a recessed cylinder. So in this way you can use one map for recessed and raised parts of your surface, with a simple solution.

Interested? tomorrow I have some with gravity controlled displacement maps.

Best regards and happy renderings,

Bopperthijs

-How can you improve things when you don't make mistakes?