cam_pos      = [-0.201074, 1.00335, 0.571961]';
cam_dir      = [-0.582511, 0.447224, -0.678728]';
cam_up       = [0.809336, 0.396398, -0.43341]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.100036, 1.06637, 0.788505]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;