Terrain LOD: Pre-computed TIN Approaches

Creating a TIN from a heightfield grid is itself a form of "lower LOD", albeit a less flexible one.  If the terrain area is small, largely piecewise flat, or won't require significant distance culling, then it can be much faster and simpler to create and render a TIN than to do continuous LOD.

Creating pre-computed TINs

Limited LOD with pre-computed TINs