while looking at the Goldrush map I noticed that sometimes in the func_explosive entity there was a origin brush (bankdoor) and somtimes there was not (rubble2) which is right?
func_explosive
sock
(sock)
#2
Its a combination of entities changing throughout a project lifecycle and different mappers working on the same map at different times of its development.
The recommendation is to include an origin brush in func_explosive entities. But as the map goldrush proves sometimes you can get anyway with it! 
Sock
:moo:
Flash95
(Flash95)
#3
thanks I am compiling a list of entitys that need a origin brush to avoid problems with my maps
damocles
(damocles)
#4
What purpose does an origin in a func_explosive serve? I can only presume it’s used to decide where debris will come from. So in a lot of cases, the centre of the brush group volume (the default) would be fine. I have to admit, I have never ever used an origin in a func_explosive and have never experienced any troubles with them. Maybe it’s about time I moved on from cube map v2 