I have been requested to upload a small tutorial I made some time ago in answer to a question at Renderotica. This no longer exists there as it and all other threads were removed some weeks ago to speed up their server (it may be back there in the meantime but I have not been there for a while). Anyway for Barbarellany and the others on thread http://www.renderosity.com/messages.ez?ForumID=12356&Form.ShowMessage=567385 here you go!