2015-06-08 Notes of Quad-Trees Culling for Terrain Rendering Quad-Trees "GPU Terrain Rendering" Game Programming Gems 6 http://alex-simon.blogspot.jp/2010/04/game-programming-gems-list-of-contents.html "Quadtrees on the GPU" GPU Pro 5 https://www.crcpress.com/product/isbn/9781482208634 etc : Horizontal Culling "Rendering the Whole Wide World on the World Wide Web" 2013 https://cesiumjs.org/presentations/Rendering%20the%20Whole%20Wide%20World%20on%20the%20World%20Wide%20Web.pdf