Ciao Keith, CAB and all others too numerous to enunciate...
Yeah, we had a major relocation of office with all the disruption of Xmas period, etc... so disappeared and when resurfacing mamma mia what a change at cadalog.
Simply 2D and plan view [like roof plan], and a user selects a polyline defining say the eaves line of building and the routine works out ridges, valleys, ridge line for a hip roof. Had a look at the straight skeleton formula, but j'y pige que pouic $ [excuse my french]!
Hope this make more sense.
P.S: is this the place to hang out?