cam_pos      = [-0.310789, 0.630353, 1.49146]';
cam_dir      = [0.880245, 0.464294, -0.0979795]';
cam_up       = [-0.401285, 0.838553, 0.36851]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.336833, 0.379131, -1.22951]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;