I had been thinking about gathering more information about the enemy gun and finally found a way to do it. If we know that a bullet shadow is safe, can't we add it to safe points to learn. A robot would be able to learn without getting hit. What do you think?
shadowed area isn’t really safe until your bullet passes enemy wave. so just do it every time enemy wave breaks.
keep tabs on shadowed area as in keeping track of hits, and retrieve them in the same way. then shadowed area could be handled like real shadows, but weighted.