Convert camera rotation from Euler angles to rotation matrix, and reverse.
misc/cam_rotation to out_rotation_matrix.json x y z
In the first form, writes a 3x3 rotation matrix to out_rotation_matrix.json, containing the rotation given by the angles in x, y, z, given in degrees.
The rotation matrix is R = transpose(R_z * R_y * R_x): The camera first does a pitch rotation around its X-axis by x degrees. Then is does a yaw rotation around its new Y-axis, by y degrees. Finally it does a roll rotation around its viewing axis, by z degrees.
The transpose is taken, because the rotation matrix R is the rotation from world space to camera space.
misc/cam_rotation from rotation_matrix.json
In the second form, reads the rotation matrix in rotation_matrix.json, and prints the corresponding x, y, z angles.