Map Vocabulary - Words to recognize

Doom map editing has a set of words that are used to describe the parts and pieces of a level. The DeePsea documentation uses these words throughout, so remembering what each part stands for will help you read the documentation effectively. The following terms comprise the basics of map editing. Following this quick overview is a more detailed explanation of how the parts relate to one another. Consult the glossary for more information on words not listed here. See A detailed look at WAD files topic for a narrative description.

Term	Definition
LineDef	LineDefs are the lines in the map. These lines define the borders of a Sector or the location of a trigger that you walk LineDefs are also called walls. A LineDef always has 2 vertices, a start and an end
Map or level	A map is a single level or mission to play.
Node building	Nodebuilding is a special (and required step) that creates nodes that tell the game how to draw walls. DeePBSP is the nodebuilder used by DeePsea, the fastest on the planet.
Sector	Sectors glue Ceiling and Floor Textures together and define a Bottom (floor) and Top (ceiling). A Sector appears visually on the map when 3 or more LineDefs connect together to form an enclosed area. Typically a Sector is a room with lighting, floor and ceiling heights, and other optional special information.
Sidedef	SideDefs glue LineDefs to Sectors. They represent each side of a LineDef. A LineDef must have at least one SideDef. Two SideDefs are required when a LineDef can be seen from both sides.
Thing	A thing defines a single object within a map. Most things interact with the player in some way, although some are strictly scenery. A few examples are weapons, ammunition, and enemies.
Vertex	Vertices are the x,y coordinates of a single point on a map. DOOM maps are 2 dimensional. The height comes from Sectors (see below). X is left to right and Y is up and down.
Wadfile	DOOM stores data about the game in files called WAD files. DeePsea edits WAD files. There are 2 types of WAD files, the main once that comes with the game (called an IWAD) and add-on files called PWADS. The two terms come from the identification IWAD or PWAD placed in the first 4 positions in the file. Wadfiles can contain maps, sounds and any other temporary modifications accepted by the engine. HEXDD.WAD for the HEXEN addon Deathkings is an IWAD internally, but treat this as a PWAD.