参考链接:
https://blog.csdn.net/u010333737/article/details/82859246
https://baike.baidu.com/item/%E6%8C%87%E6%95%B0%E5%87%BD%E6%95%B0/6013301?fr=aladdin
0.cg函数
https://www.cnblogs.com/ogrerun/p/11157324.html
1.smoothstep
2.pow
pow即指数函数
3.asd