Anton: Very impressive! I'm there already. As for the geometry switching code of JeffH: is that proprietary with you? If not & if it's not extremely advanced, many of us would love to have some insight into how you did this. If it was possible to give a tutorial or summary without divulging your innermost secrets, that is. At the very least, reading your comments might force some of us to come to a deeper understanding of geometry files. Thanks!