How to zone a roof best

[Freshmeat]

So, I have been working on a map for some time now, but the outdoor sectors are still bothering me. A sketch of the map is below:

The problem is optimization.

1) If the players are on the roof (1), the parapet prevents them from looking at anything on the ground, and vise versa. I could make some really big zone portals around it, but will large zone portals increase the time needed to figure out what gets rendered more than the time needed to actually render it?

2) Same problem between (2) and (3). The building in the middle is a separate zone. I figure that an antiportal in the wall with the door would decrease the number of objects rendered, but would this be offset by the complicated geometry with the door? The door is so far nescessary to ensure that the building is not to easy to defend.

 

[Sugarfree]

Imho you should not place huge zoneportals. Use Antiportals instead.

 

[Falidell]

well
if the roof is set up so you can't seen the floor level
then i would just use fog an cull-distance instead of useing zone portals, or alternatly you can use antiportals( just don't make complex shapes or use more then 4-6 antiportals or you could actually make the performance worse because the game engine will have to calulate drawing and such with too many antiportals.

edit: the reason for not useing zone portals is because when you actually look at the portal you render whats on the other side so if you zoned off the roof and go up there it would be no benifit... however i just can to the realization that if you made the zone portals so you couldn't see it from the ground level it would benifit performance on the ground...... and if you added fog with cull/distance that cull at least 50% of things that are on the ground when your on the roof both places would benifit....... up to you

 

[Fel]

best way for something like that is to use anti-portals

 

[Freshmeat]

Thanks for the advice. An antiportal down along the wall of the keep had the desired effect.

 

[Sugarfree]

Thanks for the advice. An antiportal down along the wall of the keep had the desired effect.

Antiportals are exactly made for this. Zone/portals are only for zoning off small spaces e.g. Doors, Windows,...

 

[Freshmeat]

Antiportals are exactly made for this. Zone/portals are only for zoning off small spaces e.g. Doors, Windows,...

I was aware of that, but I was somewhat uncertain how much they should occlude before it was worth it. I found different sources on the web, ranging from 'Only a last resort' to 'up to 20 at a time in view'. Anyway, I think this was a good solution.