2015-03-06 Notes of fractal terrains URL "Procedural Fractal Terrains" https://www.classes.cs.uchicago.edu/archive/2014/winter/23700-1/project_4_and_5/MusgraveTerrain00.pdf "terrain raymarching" by iq http://www.iquilezles.org/www/articles/terrainmarching/terrainmarching.htm "advanced perlin noise" by iq http://www.iquilezles.org/www/articles/morenoise/morenoise.htm "behind elevated" by iq. 2009 http://www.iquilezles.org/www/material/function2009/function2009.pdf "Generating Complex Procedural Terrains Using the GPU" GPU Gems 3 http://http.developer.nvidia.com/GPUGems3/gpugems3_ch01.html