how can i reproduce the 'Unity_Matrix_VP' value

Question

I wan't to calculate the Unity_Matrix_VP in C# code.

But, always I got the incorrect result. My code as follow:

     Matrix4x4 V = camera1.worldToCameraMatrix;
     Matrix4x4 P = camera1.projectionMatrix;
     var N = new Matrix4x4();
     N.SetRow(0, new Vector4(1.0f, 0.0f, 0.0f, 0.0f));
     N.SetRow(1, new Vector4(0.0f, 1.0f, 0.0f, 0.0f));
     N.SetRow(2, new Vector4(0.0f, 0.0f, -1.0f, 0.0f));
     N.SetRow(3, new Vector4(0f, 0f, 0f, 0f));
     Debug.Log("testCamera");
     Debug.Log(N);
     Debug.Log(P * N * V);

My Code result is:

0.97384 -0.02902 0.00304 3.04939 0.05073 1.72168 0.18231 179.67620 0.00624 0.10518 -0.99504 -990.16710 0.00623 0.10512 -0.99444 -989.57320

But, the value of Unity_Matrix_VP from FrameDebugger is another value:

Frame Debugger Result

It's very amazing. Could Unity calculate the unity_Matrix_VP value via another method?

Answer 1

I have got it:

Because the Unity C# use the OpenGL standard and I run Unity on Windows.

So it will translate the Matrix_PV to DirectX。

It can fixed by API of 'GL.GetGPUProjectionMatrix' to cross platform.