sv_portal_placement_never_bump
sv_portal_placement_never_bump
is a console command available in Portal. It causes Portals to always place where your crosshair is, and never make room for other portals.
Values
When set to "1" it will have the effects described above. When set to "0" it will not have any effects and the game will play as normal (Portals will always move over/not place if another portal is in the way). When set to "2" or greater, it will have the same effects as setting it to "1". (Or at least not have any noticeable effect).
Cheat Protection
sv_portal_placement_never_bump is a cheat-protected CVar and sv_cheats must be set to "1" to change the value of this CVar.
Todo: More Information should be acquired about this CVar, as there is not much documentation and it may be useful for debugging purposes.