Doomsday Engine

Often it is necessary to limit the effect of some definition or variable to a specific map, episode, game, global variable state, or perhaps even a single room in a map. This need manifests in several places:

• A mod/TC might want to override certain variables/definitions for an entire game.
• All the maps of an episode might want to use a specific sky texture.
• Particle effects may be defined for specific sectors in a map (e.g., rain).
• Light source definitions target a specific map in a game/WAD.
• Model definitions target a certain type of object in specific states.
• XG effects need to target certain lines and/or sectors (done via various XG references).

In other words, "scoping" is a universal need in the engine. There should be a uniform way to handle this a unified, powerful manner using a syntax that is consistent in all use cases.

See also: DED 2.0 and Resource URIs proposals