@Override
  public void setKnownSites(Collection<VectorXYZ> sites) {
    
    AxisAlignedBoundingBoxXZ boundingBox = new AxisAlignedBoundingBoxXZ(sites);
    boundingBox = boundingBox.pad(100);
    
    triangulation = new DelaunayTriangulation(boundingBox);
    
    for (VectorXYZ site : sites) {
      triangulation.insert(site);