I'm looking for an algorithm that converts a regular grid of heights (e.g. 1024x1024) to a triangular irregular network. Here is an image showing an example of a triangular irregular network:
I've looked in the internet for an algorithms to convert it, but I just couldn't find one. Basically the triangle density depends on the roughness and/or pixel error (when rasterized), or something like that.
I would think that a mesh simplification algorithm would do what you want. I assume that the large triangles would be a combination of nearly-co-planar triangles in an area.
Some discussion below: http://webdocs.cs.ualberta.ca/~anup/Courses/604_3DTV/Presentation_files/Polygon_Simplification/7.pdf