I use these two, but different convention from DirectXMath, so you need to do some work on the matrices.

Those are methods of a 3x3 matrix class, and so you have to swap the rows with columns on code like this: (*this)[a1][a2] → (*this)[a2][a1]

After that the code should work even if you use 4x4 matr…

The way I find up_tmp in init_camera_axis() is not optimal because if my cam->vec is (1, 1, -1) I can't find the right up_tmp. I currently find (0, 0, 1) and it should be equal to (-1, 0, 1). Do you have any idea how I can correct this ?