A geometric approach for DEMs simplification is proposed.The main idea is to uniformly pick points from DEM in the sense of geodesic metric
resulting in terrain-adaptive samples in Euclidean metric.This method randomly sample point from mesh nodes
then judge if the point can be accepted or not according to its geodesic distance from sampled point set
and repeat the whole process until no points can be added.By defining weighted geodesic distance positively related to terrain variation
results with more points in rugged terrain areas and sparse points in flat areas can be obtained.Moreover
the distribution of samples is very fit for high performance terrain visualization.This method is really simple and can retain the topographical details more effectively.