surfaceShader加cutoff和cull

在surface shader中加cutoff，参考”Legacy Shaders/Transparent/Cutout/Diffuse”

• _Cutoff (“Alpha cutoff”, Range(0,1)) = 0.5
• Tags {“Queue”=”AlphaTest” “IgnoreProjector”=”True” “RenderType”=”TransparentCutout”}
• #pragma surface surf Lambert alphatest:_Cutoff
• surf函数里记得赋值给a：o.Alpha = c.a;
• 注意：cutoff和blend会费，尽量区分开

加背面剔除选项

• [Enum(UnityEngine.Rendering.CullMode)] _Cull (“Cull Mode”, Float) = 2 //默认是back，省，双面会费
• SubShader
  {
  Tags {……}
  Cull [_Cull]
  CGPROGRAM
  ……