How a patch fills between its boundary edges. With three or four edges, coons blends the edges,
stretch is flatter and curved rounder. With two edges, stretch and coons join them as opposite
sides, while curved sweeps one along the other, so the two must share a corner.
How a patch fills between its boundary edges. With three or four edges, coons blends the edges, stretch is flatter and curved rounder. With two edges, stretch and coons join them as opposite sides, while curved sweeps one along the other, so the two must share a corner.