The Dark Engine is a game engine developed by Looking Glass Studios and was used from 1998 to 2000, mainly in the early Thief games.
Features
The Dark Engine's renderer, originally created by Sean Barrett in 1995, supports graphics similar to that of the original Quake, with Unreal-like skybox effects and colored lighting introduced in Thief II. Due to the limited hardware of the time, the Dark Engine was not designed with scalability in mind, and can therefore only display 1024 terrain polygons onscreen at once, as well as various other limits on objects and lights. In terms of textures, the game supports palletized PCX and TGA textures, in powers of two up to 256x256. Textures are grouped in "families" which share the same palette. There is a maximum of 216 textures and independent palettes, excluding 8 animated water textures. The engine does not natively support advanced game scripting, with AI and object behavior being controlled by "Object Script Module" files, which are DLLs that are loaded at runtime. As such, new modules can be written and plugged into the level editor, DromEd, but are limited due to the scope of the functions made available by the core engine. In order to overcome this, editors must resort to complicated Rube Goldberg machine-like effects using a combination of its other systems. For its time, the Dark Engine offered advanced AI and sound features, as well as a powerful object-oriented object system. The designer has full control of sound propagation within the level, and the "artificial intelligence" of the non-player characters allows for three levels of awareness: vague acknowledgement caused by mild visual or auditive disturbances, which only prompts a startled bit of dialogue; definite acknowledgement caused by significant visual or auditive disturbances, which causes the NPC to enter "search mode", and definite acquisition, prompting a direct attack.
DromEd
DromEd is the level editor for the Dark Engine. It was originally used in the design of Thief: The Dark Project, but after a petition from the fan community it was released to the public, as were later versions. There are four different versions of DromEd: for Thief: The Dark Project, for Thief Gold, for Thief II, and lastly for System Shock 2, commonly called "ShockEd." DromEd for Thief: The Dark Project and Thief Gold use the same version of the Dark Engine and therefore can open levels created for each game, although Thief Gold levels may refer to in-game objects that are not found in Thief. Thief II uses a revised version of the Dark Engine, and therefore it is difficult to open levels created for Thief with DromEd for Thief II. ShockEd is not compatible with any Dark Engine games aside from System Shock 2. However, basic level geometry can be moved between editors using a geometry export feature called "multibrush". System Shock 2 levels can be loaded by DromEd 2 with some work. The name of the level editor, DromEd, is a reference to the original project it was designed for — a game based on the Arthurian legend of Camelot — the Camel becoming Dromedary and thence Dromed. DromEd has been used by fans to create hundreds of fan missions for Thief and Thief II, and several missions for System Shock 2.
