First compiled in April of 1993, Ken Silverman's Build engine would go on to be one of the most prolific first person shooter game engines ever written. 3D Realms and Monolith Productions in particular would make waves with their games released using the engine ( Duke Nukem 3D, Shadow Warrior and Blood) while other licenses would continue to use the engine even as more advanced engines (such as the Unreal, Quake, and Lithtech engines) prospered.
- Sector-based Mapping
- Sloped Floors
- Room Over Room
- Sector Over Sector
- Vertical Movement - Jumping / Ducking / Swimming / Flying
Development on the engine began after Ken completed work on Ken's Labyrinth and had signed marketing rights over to Epic MegaGames in an attempt to create a new style of 3D engine. At the time, it still lacked a bulk of the features that it's currently known for, such as variable heights, rooms above rooms and sloped floors, and it still utilized grid-based maps. In the following month, the angled walls and varying heights would be implemented as Ken rushed to get a proper tech demo done before graduating high school.
August of 1993 marked the official beginning of Ken's employment agreement with Apogee Software and also the shift in compilers from QuickBasic to Wacom C. After talking with John Carmack over the phone, Ken rewrote the engine in January of 1994 to use sector-based maps. This cleaned up a number of previously existing drawing bugs and brought about a new found flexibility to the engine. Unfortunately, Ken's dedication to working on the engine impacted his grades at Brown University and he filed a leave of absence towards the end of the month to fully concentrate on his work.
In February of 1994, the engine was finally split into two distinct modules: the game (GAME.C) and the editor (BUILD.C). From this point on, the editor was simply called, "Build". Over the next two months, the ability to look up and down and the handling of translucent sprites were added to the engine. At this point, similar games such as Doom, Heretic and Rise of the Triad had not yet implemented similar features, though a few days after the new found viewing flexibility was incorporated in the Build engine, it was added to the Rise of the Triad engine as well.
The multiplayer component of the Build engine until this time was still only functional over a serial link hook up because of bandwidth considerations, but in June of 1994, a new method of reducing communications bandwidth by a significant margin was discovered. A week later, the first test of a Build game over a modem was completed. Network packets wouldn't be sent out at a constant interval until February of the next year, but the initial tests proved playable and extremely promising. By March of 1995, the serial and modem code was declared, "bug free".
Doom and other first person shooters had popularized the 2D wireframe map view, but in April of 1995, Ken finished a texturized version to go along with the wireframe view. Two weeks later, Hi-res mode support was added for all resolutions and in September the support for VESA 2.0 linear modes, which allowed direct framebuffer access in protected mode as one large area of memory instead of in smaller chunks. Also completed in the later half of 1995 was the formation of the GROUP (.GRP) file system and one of the engine's trademark features: slopes. Prior to the introduction of slopes, Capstone Software released the first two Build engine games, " William Shatner's TekWar" and " Witchaven".
Development on Duke Nukem 3D was drawing to a close by the end of 1995 and it was subsequently released in January of 1996. Ken continued to enhance the engine for future projects under the role of a consultant rather than an employee and in the beginning of February of 1996, he implemented voxel support, his last major contribution to the engine for a number of years. Various map developers would experiment with and push the capabilities of the engine through clever tricks, showing off features such as stacked sectors to build levels that wrapped around on themselves (as in the secret level of Duke Nukem 3D's second episode) and rooms above each other (provided only one was visible at a time).
A revived interest in the engine began in earnest with the release of the Duke Nukem 3D source code on 1 April 2003 and with the modern sourceports that followed it. Ryan Gordon and Jonathan Fowler both released early ports (to Linux and NT-based systems, respectively). While these ports proved popular with players, neither took advantage of 3D acceleration until Ken Silverman, tired of waiting for someone else to do it, wrote an OpenGL accelerated version titled, "Polymost". A major feature of the Polymost rendering engine is the support of replacement high resolution graphics, spawning multiple projects to redo the artwork of various Build engine games. Jonathan Fowler has since incorporated the Polymost engine into his Build engine ports.