Question

I found this question to perform a transformation between OpenGL and DirectX, but it doesn't seem to be working when performing the same things from Unity3D.

I was hoping that there is someone here who knows anything about the differences between an OpenGL projection matrix and the Unity3D projection matrix (and view matrix!).

I have tried to use this article as well, but it didn't work either.

In Unity3D I'm calling to my own native C++ plugin:

SetView(MatrixToArray(Camera.current.worldToCameraMatrix));
SetProjection(MatrixToArray(Matrix4x4.identity));
SetWorld(MatrixToArray(Camera.current.projectionMatrix));

private static float[] MatrixToArray(Matrix4x4 _matrix)
{
    float[] result = new float[16];

    for (int _row = 0; _row < 4; _row++)
    {
        for (int _col = 0; _col < 4; _col++)
        {
            result[_col + _row * 4] = _matrix[_row, _col];
        }
    }

    return result;
}

And in my C++ plugin I try to convert these matrices via the article:

extern "C" void EXPORT_API SetProjection(float a[])
{
    g_Proj._11 = a[0];
    g_Proj._21 = a[1];
    g_Proj._31 = -a[2];
    g_Proj._41 = a[3];
    g_Proj._12 = a[4];
    g_Proj._22 = a[5];
    g_Proj._32 = -a[6];
    g_Proj._42 = a[7];
    g_Proj._13 = a[8];
    g_Proj._23 = a[9];
    g_Proj._33 = -a[10];
    g_Proj._43 = a[11];
    g_Proj._14 = a[12];
    g_Proj._24 = a[13];
    g_Proj._34 = -a[14];
    g_Proj._44 = a[15];
}

extern "C" void EXPORT_API SetView(float a[])
{
    g_View._11 = a[0];
    g_View._21 = a[1];
    g_View._31 = -a[2];
    g_View._41 = a[3];
    g_View._12 = a[4];
    g_View._22 = a[5];
    g_View._32 = -a[6];
    g_View._42 = a[7];
    g_View._13 = -a[8];
    g_View._23 = -a[9];
    g_View._33 = a[10];
    g_View._43 = -a[11];
    g_View._14 = a[12];
    g_View._24 = a[13];
    g_View._34 = a[14];
    g_View._44 = a[15];
}

I know things are drawn, because using the identity matrix for view and projection matrix do give me a triangle for vertices: {0,0,0},{0,1,0},{1,0,0}. And I also see all sorts of shearing effects when moving my camera.

EDIT - more info:
Unity3D Documentation tells us that it uses OpenGL notation.

EDIT - example project:
If anyone wants to try out my code, I've created a test project and uploaded it to the unity forum.

Était-ce utile?

La solution

The article seems to be working just fine, but it seems that in all my rushing and trying I set the projection matrix in the world matrix.

SetProjection(MatrixToArray(Matrix4x4.identity));
SetWorld(MatrixToArray(Camera.current.projectionMatrix));

should have been

SetWorld(MatrixToArray(Matrix4x4.identity));
SetProjection(MatrixToArray(Camera.current.projectionMatrix));

I've put some more information on the unity forum about the test project.

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