how can make dynamic mask for part of render

Unity Engine
1

hi,
i write 2d game and i now i need mini map for it but i haven’t any good idea for make mini map. my mini map should something like this :
i have spot light that follow my game object and now i need mini map for my game but it shouldn’t show all thing in map. my mini map should show the path that spot light lit it and i should can save this path. now how can implement this mini map?

i think i should have blank picture and map it to my world then i change transparency of places that lit by my spot light.
then mask camera output with picture that made. and when i need save this picture for next use. is it correct way for it?

  • may game is some thing like “gem miner”.
2

sorry for poor English.
i think i cant say my problem so i add some screen shot of gem miner mini map.

how can i make mini map like this???

thanks.

3

why nobody answer me? is it wrong question or it is in wrong forum? or its very simple? if its very simple please give some references to me. for start.