Yeah, I mislead you when I said plane, it started off as a plane that has now been sculpted via displacement with a heightmap to match topographical data, enhanced in mudbox, then polygon reduced. It is in quads which are evenly distributed on X and Z but not Y.

What I want to do is wind up with 16 512x512 meshes (with matching edge vertices) that compromise the entire surface of the larger mesh when aligned together (w/o gaps). This is for occlusion culling in a video game, so that the entire terrain doesn't need to be rendered at all times, but it requires precision fit pieces to work at scale.

I can't grab a screen at the moment, but will try when I get a chance. Thank you both for the help.