https://www.jianshu.com/p/f34d896dde5d
https://blog.csdn.net/linjf520/article/details/93375272
https://www.jianshu.com/p/12cc73dc7413
https://blog.csdn.net/yangxuan0261/article/details/88692236
shader变体
原文:https://www.cnblogs.com/javalzy/p/12941957.html