Sector
From DoomWiki.org
A sector is an area referenced by Sidedefs on the Linedefs. Sectors must be closed areas, as in all sidedefs that reference they must make up a closed shape. Note that having unclosed sectors is possible, and can be used for a few special effects, but you shouldn't really attempt to use them unless you're pretty experienced in level editing since they can cause unpredictable results (including crashes).
Ceiling Flat - This is the name of the flat (texture) used to texture the floor of the sector.
Floor Flat - Same as the ceiling flag, only used on the floor.
Ceiling Height - The height of the ceiling.
Floor Height - The height of the floor.
Lighting - How bright the sector is.
Sector Tag - A number used that allows you to alter the sector's ceiling and/or floor height, lighting level or even flats.
Sector Type - A defining property of the sector. These allow you to give a sector some form of damage (for things like lava and slime), have the sectors light level change constantly, enable wind or currents or even push the player in a certain direction.
Sector Structure
For the more technical you may wish to know the actual structure that all sectors have should you decide to make some sort of WAD utility.
size | description |
2 | floor height |
2 | ceiling height |
8 | flat to apply to floor |
8 | flat to apply to ceiling |
2 | light level |
2 | special type |
2 | sector tag # |