some question

[GITHUB243884919]

hi ~ Think you and thank your code. I am learning quadtree. I have some questions.

1. In the DemoScript.Update()
   `
   // refresh QuadTree each frame if bodies can move

    _quadTree.Clear();
   
    foreach(var b in _quadTreeBodies)
   
    {
   
        _quadTree.AddBody(b);
   
    }
   

`
I understand that there is rebuild QuadTree in per frame. I know do it because bodies is moving in per frame. I think maybe there is a way that deal it without rebuild QuadTree. But I do not know. So I ask you.

2 . In the QuadTree's 2nd Constructors function
`
private QuadTree(Rect bounds, QuadTree parent)

        : this(bounds, parent._maxBodiesPerNode, parent._maxLevel)
    {
        _parent = parent;

        _curLevel = parent._curLevel + 1;

    }

`
why _maxLevel is parent._maxLevel? I think _maxLevel = parent._maxLevel - 1