The center of mass can be defined for a model during it's compile. So you could probably do it with a recompile of the model. $collisionmodelAlso, along similar lines, this is more an engine thing than a Hammer thing, but I want the ability to set a physics prop's center of gravity, either in the prop's data itself or in Hammer. It's so stupid that there's no way to tell the engine that the orange lamp is supposed to be able to stand up on its base.