Excellent information Jwatte! How would you be able to get the cylinder to work in Chaos? I use BP and not forsure how you would go about making that work. I had created a thread to get some help on making a convex cylinder work but have not gotten any help yet. If you can make a cylinder collision somehow with C++ I would love to know how, maybe a plug-in or someway to expose to BP. Collison Geometry for a Physics Based Motorcycle?