I have a hard time understanding the idea behind ROAM algorithm
- "Real-time, continuous level of detail rendering of height fields" Peter Lindstrom, David Koller, William Ribarsky, Larry F. Hodges, Nick Faust, Gregory A. Turner SAIC http://dl.acm.org/citation.cfm?id=237217
- "ROAMing terrain: real-time optimally adapting meshes" Mark Duchaineau, Murray Wolinsky, David E. Sigeti, Mark C. Miller, Charles Aldrich, Mark B. Mineev-Weinstein http://dl.acm.org/citation.cfm?id=267028
The problem that I cannot grasp is that the whole idea behind the algorithm is that the terrain mesh is at all times divided to isosceles right angled triangles but when we arrange the terrain in a non flat mesh then the triangles that we divided the mesh into are supposed to be extended(?) to meet the height field requirements?
From what perspective is the terrain divided into those triangles and should they be isosceles right angled triangles generally or only when looked upon in up-down projection?