System Matrix upon Export to DirectX

I’m exporting a mesh to DirectX…the root frame has a transformation matrix ( SystemMatrix ) that cannot be correctly converted to a quaternion. The root matrix is the following:

._11 = 1;
._12 = 0;
._13 = 0;
._14 = 0;
._21 = 0;
._22 = 0;
._23 = 1;
._24 = 0;
._31 = 0;
._32 = 1;
._33 = 0;
._34 = 0;
._41 = 0;
._42 = 0;
._43 = 0;
._44 = 1;

how was this generated? what rotation does it represent? I need a quaternion from this matrix, any ideas?

It represents switching of the y and z axis. It’s mirroring, not a rotation, therefore it can’t be converted to a quaternion.

From what I remember about DirectX, they really have the axes switched this way. Just forget about using quaternions for that. You can get the transformed coordinates directly as vector.xzyw