cam_pos      = [-0.614793, 0.911833, -0.124273]';
cam_dir      = [-0.128663, 0.168801, -0.977217]';
cam_up       = [0.991681, 0.0179769, -0.127462]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [0.00525135, 1.3107, 0.225714]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;