Zoning (UT)
This page covers zoning in pre-UT2003 versions of the Unreal Engine such as Unreal Tournament; in particular the use of zones to create physical effects.
In UT most cases maps are divided into Zones to achieve different behaviour of Actors in different regions of the map – the most obvious may be a player swimming in water. In this case the water surface will be the zone portal.
Zone Names
It's not always convenient to create a zone split to set a name for an area (in outdoor maps for example) where multiple names are required to cover a large area, and many zone portals would be visible at any one time. In this case the fact that multiple zone portals are visible (and probably overlapping) performance will most likely be hurt. There is another way. In UT you should use LocationID to override Zone location names. In UT2003 using a number of volumes to name your areas is (probably) a better approach to take. (I'll head over to the polycount board and ask eepers that one 
.
Definitions
- ZoneInfo: class specification page
- Definitions of Zone Portal & Zone
- Volume: class specification page
- Working With Volumes to your maps
Zones in Unreal Tournament
Tim Sweeney Introduction
Unreal levels can be huge; many of our game levels are pushing 20,000 world polygons. At any time, the player only sees a tiny fraction of those 20,000 polygons, typically 100-200 polygons. The engine spends a significant amount of CPU time figuring out which 200 polygons, out of a potential 20,000, are visible in each scene. Unreal employs several techniques to speed up this "visible surface determination" process. Most of these techniques are automatic, requiring no designer intervention. However, one of the most powerful techniques, zoning, requires level designers to manually place invisible polygons called "zone portals" in their levels. Zones greatly accelerate the engine's visibility calculations, and they also enable designers to create many special effects that are specific to a region of space, such as ambient lighting or modified gravity.
Zone Behaviour
The properties of a zone can be changed using the ZoneInfo actor which has to be located somewhere in the zone. There are special ZoneInfo actors for certain combinations of properties which are used frequently:
There are other ZoneInfo actors which offer additional possibilities:
External Reference
See this basic reference for Zone Technique: [Unreal Zones by Tim Sweeney]
