popupid: hull](Mapping) A set of surfaces generated by the compile tools during the map compile process. There are 4 hulls (stored in hullfiles mapname.p0 thru mapname.p3) generated for any given map. The first hull (Hull 0) stores all of the visible surfaces in the map, while the remaining three (Hulls 1 to 3) contain clipnode information for the 3 basic hull sizes.
the outside of a cocoa bean.
the "outside" skin/face plane/facets boundry of a model, including a map which is considered a model. HL & mod maps have 4 hulls, one for visual rendering and 3 for collision detection. Hull only seems to be mentioned when you have a LEAK error, or when modeling.