A zone portal is a surface which splits the BSP into Zoning. This is usually made from a sheet brush, but any brush can be added as a zone portal, and any surface can be set to be a zone portal.
To turn an area into a zone, the entire area must be isolated by zone portals. For example, a room with a single exit will become its own zone with a single zone portal. If the room has two exits, two zone portals must be placed to completely isolate the room into its own zone.
The term is often confused with a Warp Zone, which is a type of teleporter which allows the player to see through to the destination. See WarpZoneInfo for more on these.
Zone portals usually set to be in are invisible in game, and in UnrealEd will be invisible if:
- if the camera in 3D view is situated in solid space
- if realtime preview is enabled
Creating a Zone Portal
Simplest way:
- Make the red builder brush into a sheet. Set the dimensions so it either exactly touches the walls, or spills over into solid space.
- Click the Add Special button.
- In the pop-up window, select "zone portal" from the drop-down list of presets.
- Click "OK".
- Your map might now look dreadful in 3D view; the addition of a portal sometimes confuses the BSP a bit.
- rebuild
Zone Portal tips
It's a good idea to choose a particular texture for all portal surfaces, so you can easily see them.
- plain colour
- In UT, The little red texture UT Botpack.Ammocount.AmmoCountJunk is a popular choice: it stands out and it's already loaded by UnrealEd.
- transparent
- (in UT) A pure white texture such as UWindow.WhiteTexture, combined with the modulated flag allows view through the portal even when not in realtime preview. The surface can still be selected.
- labelled
- try wm_textures.Editor.ZonePortal. It's bright green with the words "Zone Portal"
- fancy
- UWindow.Icons.Background is a nice blue cloudy texture in UWindow that looks nice in the editor and stands out against most surfaces.
Which flags are set
Zone portals can be masked textures, visible textures or translucent textures.
You may see odd behaviour in UnrealEd's software view with this, for example looking through a translucent surface, areas of the map that lie beyond the water will show.