Hi, First sorry for the very general subject, but i didn't how how to describe my problem in that short subjetc line. I have a design problem(i haven't been programming for abou 2 months just because of design probs) with my scenegraph(a simple tree): I want to store the traversed form of the tree(a std::list of nodes) somewhere(atm it's stored with the root of the tree) and i thought it would be faster to update that list when adding a node to the tree and not building the list every frame from scratch. Now i have some problems with that approach. I thought i simply store an iterator for the list in every node, and when adding a children to a node it can just add itself at the right position in the list,as it has the iterator of its parent(and the iterator for its siblings). But that would mean i would be restricted to building the tree from the top(root) down(leaves) and i have to pay special attention in what order i add children to nodes. This introduces potential bug sources and is not good design(is it?). So should i just build the list from scratch each frame? or update it everytime something changes. If later: how can i accomplish that? i hope i made clear what i want. thanks in advance. regards, m4gnus