Sector

A sector is an enclosed area made up of lines in the map. Sectors are referenced by the sidedefs linked to the enclosing linedefs. Sectors must be closed areas, as in all sidedefs that reference them must make up one or more closed shapes. Note that having unclosed sectors is possible, and can be used for a few special effects, but can cause unpredictable results, including crashes, if used incorrectly.

A sector does not need to enclose only one area of the map. To avoid redundancy, two separate areas of the map can be defined by one sector, thus copying all the properties of one area to the other. However, the engine treats these separate shapes as the same sector. For instance, sounds entering one area of the sector will be heard by enemies in the other. This can be used intentionally to allow sounds generated in one area of the map to alert enemies in another, unconnected area. If two doors are the same sector, using Door_Raise on either door will cause both to open.

Specification

Bytes	Data type	Description	Notes
0-1	LE 16-bit signed	Floor height
2-3	LE 16-bit signed	Ceiling height
4-11	8-bit array	Floor texture
12-19	8-bit array	Ceiling texture
20-21	LE 16-bit signed	Light level	Vanilla Doom rounded the light level to the nearest multiple of 8, ZDoom shows unique light levels for all values
22-23	LE 16-bit unsigned	Sector special
24-25	LE 16-bit unsigned	Sector tag	For use with Action specials that refer to a sector by its tag

UDMF properties

The Universal Doom Map Format allows to set a number of properties on sectors. Unless otherwise specified, default values for integers and floats is 0, and false for booleans. They include:

Name	Type	Description
xpanningfloor	float	X texture offset of floor texture, Default = 0.0.
ypanningfloor	float	Y texture offset of floor texture, Default = 0.0.
xpanningceiling	float	X texture offset of ceiling texture, Default = 0.0.
ypanningceiling	float	Y texture offset of ceiling texture, Default = 0.0.
xscalefloor	float	X texture scale of floor texture, Default = 1.0.
yscalefloor	float	Y texture scale of floor texture, Default = 1.0.
xscaleceiling	float	X texture scale of ceiling texture, Default = 1.0.
yscaleceiling	float	Y texture scale of ceiling texture, Default = 1.0.
rotationfloor	float	Rotation of floor texture in degrees, Default = 0.0.
rotationceiling	float	Rotation of ceiling texture in degrees, Default = 0.0.
ceilingplane_a	float	Define the plane equation for the sector's ceiling. Default is a horizontal plane at 'heightceiling'. 'heightceiling' will still be used to calculate texture alignment. The plane equation will only be used if all 4 values are given.
ceilingplane_b	float
ceilingplane_c	float
ceilingplane_d	float
floorplane_a	float	Define the plane equation for the sector's floor. Default is a horizontal plane at 'heightfloor'. 'heightfloor' will still be used to calculate texture alignment. The plane equation will only be used if all 4 values are given.
floorplane_b	float
floorplane_c	float
floorplane_d	float
lightfloor	integer	The floor's light level. Default is 0.
lightceiling	integer	The ceiling's light level. Default is 0.
lightfloorabsolute	bool	true = 'lightfloor' is an absolute value. Default is relative to the owning sector's light level.
lightceilingabsolute	bool	true = 'lightceiling' is an absolute value. Default is relative to the owning sector's light level.
alphafloor	float	translucency of floor plane (only has meaning with Sector_SetPortal) Default is 1.0.
alphaceiling	float	translucency of ceiling plane (only has meaning with Sector_SetPortal) Default is 1.0.
renderstylefloor	string	floor plane renderstyle (only has meaning with Sector_SetPortal), can be "translucent" or "add", default is "translucent". (OpenGL only: not supported by ZDoom)
renderstyleceiling	string	ceiling plane renderstyle (only has meaning with Sector_SetPortal), can be "translucent" or "add", default is "translucent". (OpenGL only: not supported by ZDoom)
gravity	float	Sector's gravity. Default is 1.0.
lightcolor	integer	Sector's light color as RRGGBB value, default = 0xffffff. Removes the need for ColorSetter thing.
fadecolor	integer	Sector's fog color as RRGGBB value, default = 0x000000. Removes the need for FadeSetter thing.
desaturation	float	Color desaturation factor. 0 = none, 1 = full, default = 0. Removes the need for ColorSetter thing.
silent	bool	Actors in this sector make no sound,
nofallingdamage	bool	Falling damage is disabled in this sector
dropactors	bool	Actors drop with instantly moving floors
norespawn	bool	Players cannot respawn in this sector
soundsequence	string	The sound sequence to play when this sector moves. Placing a sound sequence thing in the sector will override this property.
hidden	bool	if true this sector will not be drawn on the textured automap.
waterzone	bool	Sector is under water and swimmable. Removes the need for using WaterZone things.
moreids	string	Additional sector tags, specified as a space-separated list of numbers, e.g., "2 666 1003 4505".
damageamount	integer	Amount of damage inflicted by this sector. Default = 0. If this is 0, all other damage properties will be ignored. Setting damage through these properties will override any damage set through sector specials. Setting this to a negative value will create a healing sector.
damagetype	string	Damage type for sector damage, Default = "None" (generic damage).
damageinterval	integer	Interval in tics between damage application. Default = 32.
leakiness	integer	Probability of leaking through radiation suit (0 = never, 256 = always). Default = 0.
damageterraineffect	bool	If true, a terrain splash is spawned at the end of each damage interval. Default = false.
damagehazard	bool	If true, the damage model is changed to Strife's delayed damage for the given sector. Default = false.
floorterrain	string	Sets the terrain for the sector's floor. Default is to use the flat texture's terrain definition.
ceilingterrain	string	Sets the terrain for the sector's ceiling. Default is to use the flat texture's terrain definition.
portal_ceil_alpha	float	Translucency of ceiling portal. The default value of 0 means "not visible".
portal_ceil_blocksound	bool	Ceiling portal blocks sound.
portal_ceil_disabled	bool	Ceiling portal is disabled.
portal_ceil_nopass	bool	Ceiling portal blocks movement if set to true.
portal_ceil_norender	bool	Ceiling portal is not rendered.
portal_ceil_overlaytype	string	Defines translucency style. It can either be "translucent" (default) or "additive".
portal_floor_alpha	float	Translucency of floor portal. The default value of 0 means "not visible".
portal_floor_blocksound	bool	Floor portal blocks sound.
portal_floor_disabled	bool	Floor portal is disabled.
portal_floor_nopass	bool	Floor portal blocks movement if set to true.
portal_floor_norender	bool	Floor portal is not rendered.
portal_floor_overlaytype	string	Defines translucency style. It can either be "translucent" (default) or "additive".
noattack	bool	If true, monsters in the sector do not attack.