Horizon of a convex polyhedron
= Horizon of a convex polyhedron
For an external viewpoint in general position, the horizon is the cycle of edges separating visible and nonvisible faces of a <convex polyhedron>. In the <incremental three-dimensional convex hull algorithm>, retain these edges, remove visible faces, and join the viewpoint to each horizon edge to form the new faces. Edges incident with two removed faces disappear.