have a point of origin. For point entities
and many brush entities
, this point is largely irrelevant, simply being used to define where the entity is located.
Brush entities use the exact center of the map
as the origin by default. However, for some moving brush entities (such as func_trains
), the origin is used to define how the entity moves, and need to have an origin at a particular point relative to the entity. In these cases, the point of origin can be defined manually by having the entity include a brush
covered in the "origin" texture
(known as an origin brush). If the entity includes an origin brush, the point of origin will be the exact center of that brush. (The size of this brush does not matter.)