First level-of-detail

This cyber landscape is a wire-model of the heightmap I've loaded. You can cleary see the landscape being divided in 4 "chunks". Each chunk has a simple level-of-detail algorithm: if the distance between the center of chunk, and the camera is big enough, the number of "patches" for each chunk is divided by a power of 2.

Now I just need to figure out how to sew these chunks together with their neighbours, because there are wide gaps between all of 'm.