Thanks very much for your suggestion and I have read the article, and the article provides me some new perspectives. However, I have decide to do some kind of structure like trees, so I really need some one to show me some examples of "tree" structure.
I know it is quite an old post but did you find any solution to your problem?
I am looking in creating a tall tree like structure for a tower and it has been rather tricky with a lot of scattered information.
Thank you.