学习资料：https://www.jianshu.com/p/c65e2837290f
贴图旋转 http://www.manew.com/thread-139861-1-1.html
场景：守望先锋-花村 http://www.element3ds.com/thread-160496-1-1.html
场景：日式和风 http://www.element3ds.com/thread-169767-1-1.html
大佬代码工具库：https://github.com/vgvgvvv?tab=repositories
LOD四叉树：https://blog.csdn.net/cccstudyer/article/details/25139793
四叉树图解及代码(unity)： https://blog.csdn.net/u010019717/article/details/80789271
开放世界都需要哪些技术：https://www.zhihu.com/question/26538198
https://www.cnblogs.com/geniusalex/archive/2013/02/24/2924071.html
megatexture：http://218.106.254.201/download/id_tech5_clipmap.pdf
