Culling

Culling is when you try to reject objects that can not be seen as soon as possible. Objects in this case can be any amount of surfaces.

Frustum: What is visible inside your view.

Portals: Use 'doors' to find out if you can see things on the other side.

Potentially Visible Sets: Precalculate what is visible.

Occlusion Culling: Render things to learn if they are visible.

Hierarchical: If you can't see the boss the minions is invisible.

Software VRS with Visibility Buffer Rendering

http://filmicworlds.com/blog/software-vrs-with-visibility-buffer-rendering/