def METHOD_NAME(self, proj_mat):
    res = cv2.decomposeProjectionMatrix(proj_mat)
    int_mat, rot_mat, camera_center_homo = res[0], res[1], res[2]
    camera_center = camera_center_homo[0:3] / camera_center_homo[3]
    camera_center = camera_center.reshape(-1)
    int_mat = int_mat / int_mat[2][2]
    self.set_intrinsic_matrix(int_mat)
    self.set_rotation_matrix(rot_mat)
    self.center = camera_center
    self.sanity_check()