https://docs.unity3d.com/550/Documentation/Manual/SL-PlatformDifferences.html
Render Texture coordinates
Vertical Texture coordinate conventions differ between two types of platforms: Direct3D-like and OpenGL-like.
- Direct3D-like: The coordinate is 0 at the top and increases downward. This applies to Direct3D, Metal and consoles.
- OpenGL-like: The coordinate is 0 at the bottom and increases upward. This applies to OpenGL and OpenGL ES.
這個render texture之前做都是 把sample分兩種 到backbuffer的和到中間rt的 不同平臺 中間rt的 sample不同處理 用巨集
cmd.DrawMesh(fullscreenTriangle, Matrix4x4.identity, propertySheet.material, 0, pass, propertySheet.properties);
用這個matrix 調換的話 會有正反面的問題 cullface那裡會去掉的 不妥
nvn裡面有個編譯指令能統一設定upper down
unity的話 官方文件說 dxlike unity內部會自己flip
我android上面是對的 同樣的程式碼 iphone反了 ogl和metal的差