Make holes for landscape in landscape material dynamically?

Is it somehow possible?
I have random generated cave system underneath the ground and in each game session I want to have randomly placed cave entries.
Right now I made like 10 holes and by default all of them are hidden within rock mesh and in each game session some of them are replaced with cave entry mesh.
It works fine now, but player can learn these locations and just check them each time he play :<
Can I somehow pass vectors with positions and “size” into landscape hole material during runtime and hide polygons?