Peter Lindstrom David Koller William Ribarsky Larry F. Hodges Nickolas Faust Gregory A. Turner Real-Time, Continuous Level of Detail Rendering of Height Fields. 109-118 1996 SIGGRAPH http://doi.acm.org/10.1145/237170.237217 db/conf/siggraph/siggraph1996.html#LindstromKRHFT96