cam_pos      = [-0.491128, 1.0117, 1.6784]';
cam_dir      = [0.880245, 0.464294, -0.0979795]';
cam_up       = [-0.417994, 0.856415, 0.303041]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.298734, 0.300309, -1.26074]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;