Build-Engine

In the build engine is a 3D engine for computer games, which was developed by Ken Silverman for 3D Realms and was first used in the first-person shooter Duke Nukem 3D. The engine is similar to that of a few years older Doom engine ( id Tech 1 also ).

Development

Ken Silverman began the development of the build engine in March 1993. During this time he had the full version of his first commercially successful game, Ken 's Labyrinth, completed for Epic. This game was also based on a completely self-developed 3D engine, which was technically similar to Wolfenstein 3D. With "Build" is Silverman clearly oriented to the standards that had put Doom. Technically, however, some other approaches have been followed - "Build" is thus not merely a clone of the Doom engine dar.

Technology

Former first-person shooter engines such as 3D -known Wolfenstein use the comparatively fast ray casting for the representation of three-dimensional, shown from the first-person perspective game world. "Build" this technology greatly expands and combines fast two-dimensional, ajar to ray-casting approaches with those who come in later with real three-dimensional graphics engines to use. The level geometry is based on a two-dimensional floor plan and is therefore significant limitations subject to the need to consider the level designer and the partial effect on the degrees of freedom of the player. It is for example not possible to look straight up or down. Multi-level structures - for example, bridges or buildings with several floors - can only be displayed with tricks. Engines of this type are also pejoratively called " 2.5D Engines".

In contrast to Ken 's Labyrinth and other earlier engines (such as those used in Wolfenstein 3D or System Shock ) are the floor plans in the build engine is not bound to a solid square grid. Walls must be vertical, but can at any angle meet. Furthermore, the engine different height values ​​as well as tilting of floors and ceilings allowed. The level designers made ​​this possible to give a much more intense three-dimensional feel, as the level geometry was not confined to a plane. To avoid the still existing restriction, various tricks have been applied. In the first Build - game Duke Nukem 3D, some areas actually are not one above the other, as the level architecture suggests; the player will each teleport only at the right moment unnoticed to a different location of the level. Examples include immersion in underwater areas, or jump into shafts. Spiral staircases and similar constructions with overlapping spaces are possible, but the level designers must ensure that the player can never see more than one level at a time.

Solution of the visibility problem

Regarding the evaluation mechanism for visible surfaces, to build behaves like a portal engine. The atomic sections of the level, called in build 'sectors' are by special connecting surfaces ( " portals " ) joined together. The algorithm follows all visible sectors and then displays them, the algorithms used and the method of data organization, however, differ from other engines. Silverman used a combination of an exact depth sorting and vertical tension buffer for the evaluation of the spatial depth of each pixel on the screen. If a portal into the valid depth range, the sector and all sectors contained therein is rendered. The sorting method ensures that all the surfaces are shown in the correct order.

The sectors system and the exact visibility evaluation at run time enabled a hitherto -before-seen level dynamics. Sectors were freely movable and could - depending on the creativity of the designer level - represent everything imaginable. Typical examples of moving sectors are elevators, doors, destructible walls or moving objects such as cars and subways, with which the player sometimes could even move. In a static level geometry such as the BSP system used in Doom effects of this kind were difficult and often not possible.

Objects

For enemies, items and other objects, two-dimensional sprites, as at that time typically used, which always point towards the player ( Billboard ). In addition, sprites can also be arranged rigidly vertically or horizontally, which is used in the games, for example, traffic signs or simple bridge structures.

In later build versions also voxel objects are used, for example in Blood or Shadow Warrior.

Dissemination

The build engine is measured by the number of commercial titles, probably the most widely used 3D engine of the 1990s.

• Games, which were created directly with the build engine: Blood ( 1997)
• Duke Nukem 3D ( 1996)
• Exhumed ( Powerslave in the U.S. ) ( 1996)
• Shadow Warrior ( 1997)
• William Shatner 's TekWar (1995 )
• Witchaven (1995 )
• Witchaven II: Blood Vengeance (1996 )

• Extreme Paintbrawl (1998)
• NAM (1998)
• Redneck Deer Huntin ' (1997)
• Redneck Rampage (1997)
• Redneck Rampage Rides Again (1998)
• WW2 GI ( 1999)

• Legend of the Seven Paladins ( never published, as the build engine was used without a license )
• Fate ( never completed, a demo version exists )
• Corridor 8: Galactic Wars ( never published, the sources were released)