public override ref PointNormal At(int col, int row) => ref Unsafe.AsRef <PointNormal>(Invoke.pointcloud_pointnormal_at_colrow(_ptr, col, row));
public override ref PointNormal At(int col, int row) => ref Unsafe.AsRef <PointNormal>(Invoke.pointcloud_pointnormal_at_colrow(_ptr, col, row));