cam_pos      = [-0.204794, 1.72933, 1.87041]';
cam_dir      = [0.792729, -0.488374, -0.364791]';
cam_up       = [0.276783, 0.821567, -0.498417]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.722342, -0.391209, -1.04598]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;