Corners and edges are rarely used that way. They should be. See "Fitts Law".[1]

My metaverse client normally presents a clean 3D view of the world. If you bring the cursor to the top or bottom of the screen, the menu bar and controls appear. They stay visible as long as the cursor is over some control, then, after a few seconds, they disappear.

This seems to be natural to users. I deliberately don't explain it, but everybody finds the controls, because they'll move the mouse and hit an edge.

[1] https://en.wikipedia.org/wiki/Fitts%27s_law