static public IEnumerable <T> GetItemsWithin <T>(this BoundsTree <T> item, Plane plane)
{
return(item.GetItemsWithin(b => b.IsIntersecting(plane)));
}
public IEnumerable <Triangle3> GetTrianglesWithin(Bounds bounds)
{
return(triangles.GetItemsWithin(bounds).Convert(t => t.triangle));
}