Build engine
Encyclopedia
The Build engine is a first-person shooter engine
created by Ken Silverman
for 3D Realms
. Like the Doom engine
, the Build engine represents its world on a two-dimensional
grid using closed 2D shapes called sectors, and uses simple flat objects called sprites to populate the world geometry with objects. It is generally considered to be a 2.5D
engine as the basic world geometry is two-dimensional, with an added height component, allowing each sector to have a different ceiling and floor height, and allowing them to be angled along one line of the sector. The engine renders the world in a way that looks three-dimensional; however, the sizing for perspective only depends on the horizontal distance. This is noticeable in that wall vertices are always straight vertical lines on screen, regardless of the angle of view. Therefore, with no vertical distance paramaters (only horizontal), this can cause small size distortion when looking up and down but generally it is barely noticeable. However, this distortion can be severe if the player is looking at a structure that is very tall. As an example, in Duke Nukem 3D's first level, "Hollywood Holocaust", the player can look up from the street but not see the top of the buildings as he should be able to. Instead as he looks higher, the building gets wider. As such, most Build games restrict objects vertical height to a fairly limited range (usually).
.
Developers of games based on the engine used reserved sprites, often called sector effectors, that when given special tags (numbers with defined meanings), would allow the level designer to make a dynamic world; similar tag information could be given to the sector walls and floor area to give a sector special characteristics. For example, a particular sector effector may let a player fall through the floor if he walked over it and teleport him to another sector; in practice, this could be used to create the effect of falling down a hole to a bigger room or creating a body of water that could be jumped into to explore underwater. A sector could be given a tag that made it behave like a simple elevator or lift.
Sectors could overlap one another provided they could not be seen at the same time (if two overlapping sectors were seen at the same time a corrupted display resulted). This allowed the designers to create, for instance, air ducts that appeared to extend across the top of another room (however doing so could be tricky for designers due to the 2D viewpoint used for much of the editing process). More interestingly, this allowed the designer to create worlds that would be physically impossible (e.g. a door way of a small building could lead into a network of rooms that was larger than the building itself). While all these things made the game appear to be 3D, it wouldn't be until later first-person shooter
s, like Quake, that the engine actually stored the world geometry as true 3D information.
s. This feature appeared too late to be used in Duke Nukem 3D
but was seen in several of the later Build engine games. Blood
uses voxels for weapon and ammo pickups, powerups, and occasionally eye-candy (such as the tombstones in the "Cradle to Grave" level, some chairs and a crystal ball
in "Dark Carnival"). Shadow Warrior
makes even more advanced use of the technology, with voxels that can be placed on walls (all of the game's switches and buttons are voxels) and even a rudimentary 3D enemy mode that can be toggled via the F5 key, and replaces all of the game's enemy sprites with voxels. This is extremely buggy, and seems to be little more than an unfinished test mode. It featured more prominently in the leaked Shadow Warrior beta.
For several years Ken worked on a modern engine based entirely on voxels, known as Voxlap.
A feature added to EDuke32 in 2011 is true room over room (TROR). This allows sectors to be placed on top of other sectors where both can be viewed at the same time, creating true three dimensional situations. The difference between ROR and TROR is that in TROR, the sectors are physically overlapping in the map editor (allowing for easy creation and visualization), rather than in separate locations and rendered to appear overlapping as in ROR. Hence true room over room. It should be noted that TROR is an engine feature of EDuke32, not a game feature or trick.
, it was used for many other games. It is usually considered that the "Big Four" Build engine games are Duke Nukem 3D
, Shadow Warrior
, Blood
and Redneck Rampage
, though sometimes the latter is omitted.
.
for modders
—was sent to 3D Realms for packaging. Unfortunately, it was sent just after the release of the build source and hence Duke Nukem 3D was stuck with the build libraries that 3D Realms had used in the original Duke. (Both Duke Nukem 3D and EDuke were still closed-source at this point.)
With the 2.1 private betas, Saettler worked towards integrating Silverman's build source into the Duke source code, but the project fizzled out before producing anything more than some very buggy private betas. A few total conversion teams for Build games decided to work from Silverman's Build code directly, and an enhanced version of the Build editor known as mapster
was also developed.
It was claimed at the time by many on the 3D Realms forums that it would be impossible to port Build to a multitasking OS, as it needed a large contiguous block of memory that wouldn't be available in a multitasking environment. This statement did not hold up to scrutiny, as all modern operating systems use virtual memory
which allows apps to get contiguous logical memory without using contiguous physical memory, but conventional wisdom of the time was that porting Build to such an OS was unfeasible.
and other Unix
Operating Systems, and interest in the ports soared.
(icculus), with the help of others, made the first port of the engine using SDL
. The port was first to Linux
, then to Cygwin
and finally to a native Windows build using the Watcom C++ compiler, which was the compiler used for the original DOS build. (Despite being compiled with Watcom C++, Build is plain C.) There was some talk of Matt Saettler using this to port Eduke to Windows, but nothing came of it.
The Polymost renderer allowed for 3D hardware-accelerated graphics using OpenGL
. It also introduced "hightile," a feature that made it possible to replace the game's original textures with high-resolution replacements in a variety of formats.
Polymost has been utilized in Jonathon Fowler's JFBuild, JFDuke3D, JFSW, and ports derived from their codebases.
Source for the last private beta of Eduke 2.1 (which never made it to a release version) was also released soon after the EDuke 2.0 source.
Recent releases of Eduke32 do also work with Nam and WW2 GI as the code to these games was included in the original Eduke. The Transfusion project aimed to re-create Blood
in the DarkPlaces engine, but as of 2006, this project is far from complete, though it has complete deathmatch multiplayer.
The Shadow Warrior
source was released on April 1, 2005, and JonoF released a port of it on April 2, 2005. However, he admitted that he had access to the Shadow Warrior source code about a week before its release.
The source code of Witchaven
, Witchaven II
, Tekwar and Corridor 8 have also surfaced. The legal status of these, however, is unclear.
First-person shooter engine
A first-person shooter engine is a video game engine specialized for simulating 3D environments for use in a first-person shooter video game. First-person refers to the view where the players see the world from the eyes of their characters...
created by Ken Silverman
Ken Silverman
Ken Silverman is a game programmer, best known for writing the Build engine used in Duke Nukem 3D, Shadow Warrior, Blood, and more than a dozen other games in the mid- to late-1990s...
for 3D Realms
3D Realms
3D Realms is a current video game publisher and former video game developer based in Garland, Texas, United States, established in 1987...
. Like the Doom engine
Doom engine
The Doom engine is the game engine that powers the id Software games Doom and Doom II. It is also used by HeXen, Heretic, Strife, Freedoom, and HacX, and other games produced by licensees. It was created by John Carmack, with auxiliary functions written by Mike Abrash, John Romero, Dave Taylor and...
, the Build engine represents its world on a two-dimensional
2D computer graphics
2D computer graphics is the computer-based generation of digital images—mostly from two-dimensional models and by techniques specific to them...
grid using closed 2D shapes called sectors, and uses simple flat objects called sprites to populate the world geometry with objects. It is generally considered to be a 2.5D
2.5D
2.5D , 3/4 perspective and pseudo-3D are terms used to describe either:* 2D graphical projections and techniques which cause a series of images or scenes to fake or appear to be three-dimensional when in fact they are not, or* gameplay in an otherwise three-dimensional video game that is...
engine as the basic world geometry is two-dimensional, with an added height component, allowing each sector to have a different ceiling and floor height, and allowing them to be angled along one line of the sector. The engine renders the world in a way that looks three-dimensional; however, the sizing for perspective only depends on the horizontal distance. This is noticeable in that wall vertices are always straight vertical lines on screen, regardless of the angle of view. Therefore, with no vertical distance paramaters (only horizontal), this can cause small size distortion when looking up and down but generally it is barely noticeable. However, this distortion can be severe if the player is looking at a structure that is very tall. As an example, in Duke Nukem 3D's first level, "Hollywood Holocaust", the player can look up from the street but not see the top of the buildings as he should be able to. Instead as he looks higher, the building gets wider. As such, most Build games restrict objects vertical height to a fairly limited range (usually).
Sectors
Sectors could be manipulated in real-time; their shape, heights, and slope angles being completely variable, without requiring recalculation of rendering information. This allowed games to have destructible environments, such as those seen in BloodBlood (computer game)
Blood is a PC game developed by 3D Realms and Monolith Productions and distributed by GT Interactive. Development was underway at 3D Realms in parallel with a number of other well-known titles. Following the success of Duke Nukem 3D, development progress was made public starting in June 1996 with...
.
Developers of games based on the engine used reserved sprites, often called sector effectors, that when given special tags (numbers with defined meanings), would allow the level designer to make a dynamic world; similar tag information could be given to the sector walls and floor area to give a sector special characteristics. For example, a particular sector effector may let a player fall through the floor if he walked over it and teleport him to another sector; in practice, this could be used to create the effect of falling down a hole to a bigger room or creating a body of water that could be jumped into to explore underwater. A sector could be given a tag that made it behave like a simple elevator or lift.
Sectors could overlap one another provided they could not be seen at the same time (if two overlapping sectors were seen at the same time a corrupted display resulted). This allowed the designers to create, for instance, air ducts that appeared to extend across the top of another room (however doing so could be tricky for designers due to the 2D viewpoint used for much of the editing process). More interestingly, this allowed the designer to create worlds that would be physically impossible (e.g. a door way of a small building could lead into a network of rooms that was larger than the building itself). While all these things made the game appear to be 3D, it wouldn't be until later first-person shooter
First-person shooter
First-person shooter is a video game genre that centers the gameplay on gun and projectile weapon-based combat through first-person perspective; i.e., the player experiences the action through the eyes of a protagonist. Generally speaking, the first-person shooter shares common traits with other...
s, like Quake, that the engine actually stored the world geometry as true 3D information.
Voxels
Later versions of Ken's Build engine allowed game selected art tiles to be replaced by 3D objects made of voxelVoxel
A voxel is a volume element, representing a value on a regular grid in three dimensional space. This is analogous to a pixel, which represents 2D image data in a bitmap...
s. This feature appeared too late to be used in Duke Nukem 3D
Duke Nukem 3D
Duke Nukem 3D is a first-person shooter computer game developed by 3D Realms and published by GT Interactive Software. The full version was released for the PC . It is a sequel to the platform games Duke Nukem and Duke Nukem II published by Apogee...
but was seen in several of the later Build engine games. Blood
Blood (computer game)
Blood is a PC game developed by 3D Realms and Monolith Productions and distributed by GT Interactive. Development was underway at 3D Realms in parallel with a number of other well-known titles. Following the success of Duke Nukem 3D, development progress was made public starting in June 1996 with...
uses voxels for weapon and ammo pickups, powerups, and occasionally eye-candy (such as the tombstones in the "Cradle to Grave" level, some chairs and a crystal ball
Crystal ball
A crystal ball is a crystal or glass ball believed by some people to aid in the performance of clairvoyance. It is sometimes known as a shew stone...
in "Dark Carnival"). Shadow Warrior
Shadow Warrior
Shadow Warrior, often known by its initials SW, is a first-person shooter computer game developed by 3D Realms and released on May 13, 1997 by GT Interactive. Shadow Warrior was developed using Ken Silverman's Build engine and improved on 3D Realms' previous Build engine game, Duke Nukem 3D...
makes even more advanced use of the technology, with voxels that can be placed on walls (all of the game's switches and buttons are voxels) and even a rudimentary 3D enemy mode that can be toggled via the F5 key, and replaces all of the game's enemy sprites with voxels. This is extremely buggy, and seems to be little more than an unfinished test mode. It featured more prominently in the leaked Shadow Warrior beta.
For several years Ken worked on a modern engine based entirely on voxels, known as Voxlap.
Room over room
Several Build engine games used a trick involving rendering multiple times to draw two sectors that were joined floor to ceiling. As building the sectors over top of each other was not really feasible due to limitations of the editor, the sectors could either be moved at map load time (which made calculations during the game simpler), or left where they were. The two best known games to use this trick were Shadow Warrior (which moved the sectors at map load time) and Blood (which did not). This was not a feature of the Build engine but rather a trick that was discovered by game developers.A feature added to EDuke32 in 2011 is true room over room (TROR). This allows sectors to be placed on top of other sectors where both can be viewed at the same time, creating true three dimensional situations. The difference between ROR and TROR is that in TROR, the sectors are physically overlapping in the map editor (allowing for easy creation and visualization), rather than in separate locations and rendered to appear overlapping as in ROR. Hence true room over room. It should be noted that TROR is an engine feature of EDuke32, not a game feature or trick.
Build engine games
Though the Build engine achieved most of its fame as a result of powering the classic first person shooter Duke Nukem 3DDuke Nukem 3D
Duke Nukem 3D is a first-person shooter computer game developed by 3D Realms and published by GT Interactive Software. The full version was released for the PC . It is a sequel to the platform games Duke Nukem and Duke Nukem II published by Apogee...
, it was used for many other games. It is usually considered that the "Big Four" Build engine games are Duke Nukem 3D
Duke Nukem 3D
Duke Nukem 3D is a first-person shooter computer game developed by 3D Realms and published by GT Interactive Software. The full version was released for the PC . It is a sequel to the platform games Duke Nukem and Duke Nukem II published by Apogee...
, Shadow Warrior
Shadow Warrior
Shadow Warrior, often known by its initials SW, is a first-person shooter computer game developed by 3D Realms and released on May 13, 1997 by GT Interactive. Shadow Warrior was developed using Ken Silverman's Build engine and improved on 3D Realms' previous Build engine game, Duke Nukem 3D...
, Blood
Blood (computer game)
Blood is a PC game developed by 3D Realms and Monolith Productions and distributed by GT Interactive. Development was underway at 3D Realms in parallel with a number of other well-known titles. Following the success of Duke Nukem 3D, development progress was made public starting in June 1996 with...
and Redneck Rampage
Redneck Rampage
Redneck Rampage is a 1997 first-person shooter game designed by Xatrix Entertainment and published by Interplay. The game features songs by Mojo Nixon, Reverend Horton Heat, Beat Farmers and other Psychobilly artists. As the name implies, Redneck Rampage has many hillbilly elements in it...
, though sometimes the latter is omitted.
- Games that were built directly on the Build engine.
- William ShatnerWilliam ShatnerWilliam Alan Shatner is a Canadian actor, musician, recording artist, and author. He gained worldwide fame and became a cultural icon for his portrayal of James T...
's TekWar (1995) - WitchavenWitchavenWitchaven is a fantasy computer game developed by Capstone Software and released by Intracorp Entertainment in . It was followed by the sequel named Witchaven II: Blood Vengeance in 1996.-Story:...
(1995) - Duke Nukem 3DDuke Nukem 3DDuke Nukem 3D is a first-person shooter computer game developed by 3D Realms and published by GT Interactive Software. The full version was released for the PC . It is a sequel to the platform games Duke Nukem and Duke Nukem II published by Apogee...
(1996) - PowerSlave (Exhumed in Europe) (1996)
- Witchaven II: Blood Vengeance (1996)
- BloodBlood (computer game)Blood is a PC game developed by 3D Realms and Monolith Productions and distributed by GT Interactive. Development was underway at 3D Realms in parallel with a number of other well-known titles. Following the success of Duke Nukem 3D, development progress was made public starting in June 1996 with...
(1997) - Shadow WarriorShadow WarriorShadow Warrior, often known by its initials SW, is a first-person shooter computer game developed by 3D Realms and released on May 13, 1997 by GT Interactive. Shadow Warrior was developed using Ken Silverman's Build engine and improved on 3D Realms' previous Build engine game, Duke Nukem 3D...
(1997)
- William Shatner
- Games that were based on the Duke Nukem 3D code
- Extreme PaintbrawlExtreme PaintbrawlExtreme Paintbrawl is a paintball video game released for Microsoft Windows/DOS on October 20, 1998. The game uses a modified version of the Duke Nukem 3D: Atomic Edition v1.5 executable.-Criticism:...
(1998) - NAMNAM (video game)NAM is a commercial Build engine game designed by the TNT Team , the makers of the Platoon TC for Duke Nukem 3D. Infogrames picked them up and put them to work remaking Platoon with more professional art and some custom source code modifications by Matt Saettler, who is the progenitor of the EDuke...
(1998) - Redneck Deer Huntin' (1998)
- Redneck RampageRedneck RampageRedneck Rampage is a 1997 first-person shooter game designed by Xatrix Entertainment and published by Interplay. The game features songs by Mojo Nixon, Reverend Horton Heat, Beat Farmers and other Psychobilly artists. As the name implies, Redneck Rampage has many hillbilly elements in it...
(1997) - Redneck Rampage Rides Again (1998)
- WW2 GI (1999)
- Extreme Paintbrawl
- Unreleased Build games
- Legend of the Seven Paladins (completed but never released, used the Build engine illegally)
- Fate (not completed, only a demo exists)
- Corridor 8: Galactic Wars (never released, source code available)
Source release and further developments
On June 20, 2000 (according to his website) Ken Silverman released the Build engine source codeSource code
In computer science, source code is text written using the format and syntax of the programming language that it is being written in. Such a language is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source...
.
Early days
Version 2.0—the only official binary release of Matt Saettler's Eduke, a project to improve Duke Nukem 3DDuke Nukem 3D
Duke Nukem 3D is a first-person shooter computer game developed by 3D Realms and published by GT Interactive Software. The full version was released for the PC . It is a sequel to the platform games Duke Nukem and Duke Nukem II published by Apogee...
for modders
Modding
Modding is a slang expression that is derived from the verb "modify". Modding refers to the act of modifying a piece of hardware or software or anything else for that matter, to perform a function not originally conceived or intended by the designer...
—was sent to 3D Realms for packaging. Unfortunately, it was sent just after the release of the build source and hence Duke Nukem 3D was stuck with the build libraries that 3D Realms had used in the original Duke. (Both Duke Nukem 3D and EDuke were still closed-source at this point.)
With the 2.1 private betas, Saettler worked towards integrating Silverman's build source into the Duke source code, but the project fizzled out before producing anything more than some very buggy private betas. A few total conversion teams for Build games decided to work from Silverman's Build code directly, and an enhanced version of the Build editor known as mapster
Mapster
Mapster is an enhanced version of the Build Editor, the map editor for computer games using the Build Engine, including Duke Nukem 3D and Shadow Warrior...
was also developed.
It was claimed at the time by many on the 3D Realms forums that it would be impossible to port Build to a multitasking OS, as it needed a large contiguous block of memory that wouldn't be available in a multitasking environment. This statement did not hold up to scrutiny, as all modern operating systems use virtual memory
Virtual memory
In computing, virtual memory is a memory management technique developed for multitasking kernels. This technique virtualizes a computer architecture's various forms of computer data storage , allowing a program to be designed as though there is only one kind of memory, "virtual" memory, which...
which allows apps to get contiguous logical memory without using contiguous physical memory, but conventional wisdom of the time was that porting Build to such an OS was unfeasible.
Duke Nukem 3D source release
On April 1, 2003, after several years of claims to the contrary, 3D Realms released the source code to Duke Nukem 3D. Not long afterwards, both Ryan C. Gordon and Jonathon Fowler created and released ports. It was possible to play Duke Nukem 3D well on the NT line of Windows (including Windows 2000/XP) and on LinuxLinux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
and other Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
Operating Systems, and interest in the ports soared.
icculus.org port
Ryan C. GordonRyan C. Gordon
Ryan C. Gordon is a former Loki Software employee who is now responsible for icculus.org, which hosts many Loki Software projects as well as several new projects created by himself and others...
(icculus), with the help of others, made the first port of the engine using SDL
Simple DirectMedia Layer
Simple DirectMedia Layer is a cross-platform, free and open source multimedia library written in C that presents a simple interface to various platforms' graphics, sound, and input devices....
. The port was first to Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
, then to Cygwin
Cygwin
Cygwin is a Unix-like environment and command-line interface for Microsoft Windows. Cygwin provides native integration of Windows-based applications, data, and other system resources with applications, software tools, and data of the Unix-like environment...
and finally to a native Windows build using the Watcom C++ compiler, which was the compiler used for the original DOS build. (Despite being compiled with Watcom C++, Build is plain C.) There was some talk of Matt Saettler using this to port Eduke to Windows, but nothing came of it.
JonoF port
A second port was made to Windows, and later to Linux, by Jonathon Fowler (JonoF). This port didn't have network game support until much later, and then only worked with two players.Polymost
The task of updating the Build engine to a true 3D renderer was taken on by Silverman himself. In the release notes for JFDuke3D, he wrote:"When 3D Realms released the Duke Nukem 3D source code, I thought somebody would do a OpenGL or Direct3D port. Well, after a few months passed, I saw no sign of somebody working on a true hardware-accelerated port of Build, just people saying it wasn't possible. Eventually, I realized the only way this was going to happen was for me to do it myself."
The Polymost renderer allowed for 3D hardware-accelerated graphics using OpenGL
OpenGL
OpenGL is a standard specification defining a cross-language, cross-platform API for writing applications that produce 2D and 3D computer graphics. The interface consists of over 250 different function calls which can be used to draw complex three-dimensional scenes from simple primitives. OpenGL...
. It also introduced "hightile," a feature that made it possible to replace the game's original textures with high-resolution replacements in a variety of formats.
Polymost has been utilized in Jonathon Fowler's JFBuild, JFDuke3D, JFSW, and ports derived from their codebases.
Polymer
On april 1st 2009, an OpenGL shader model 3.0 renderer was revealed to have been developed for EDuke32, labeled as the Polymer renderer (to distinguish from Ken Silverman's Polymost). At first it was thought to be an April fools joke, but the renderer was later made public. It allows for much more modern effects such as real-time dynamic colored lighting and shadow mapping, specular and normal map support, and other shader based features in addition to most of the features added to Polymost over the years. Although Polymer is completely usable, it is technically incomplete and unoptimised, and is still in development. As of the 5th installment of the High Resolution Pack (released in 2011), the Polymer renderer is mandatory. The developers of EDuke32 have stated that once Polymer has been rewritten for speed, it will replace Polymost completely, as it is a superior renderer, and can be made to look identical to Polymost.Other ports
The source for Eduke 2.0 was released, but it took a while because some people had problems compiling the archived source. This was merged with the JonoF port of Duke Nukem 3D, and many features from 2.1.1 and various other Eduke branches were added by TerminX to make Eduke32. Another port based on the icculus code, Wineduke, has since died off, leaving Eduke32 the only Eduke port still in development.Source for the last private beta of Eduke 2.1 (which never made it to a release version) was also released soon after the EDuke 2.0 source.
Recent releases of Eduke32 do also work with Nam and WW2 GI as the code to these games was included in the original Eduke. The Transfusion project aimed to re-create Blood
Blood (computer game)
Blood is a PC game developed by 3D Realms and Monolith Productions and distributed by GT Interactive. Development was underway at 3D Realms in parallel with a number of other well-known titles. Following the success of Duke Nukem 3D, development progress was made public starting in June 1996 with...
in the DarkPlaces engine, but as of 2006, this project is far from complete, though it has complete deathmatch multiplayer.
The Shadow Warrior
Shadow Warrior
Shadow Warrior, often known by its initials SW, is a first-person shooter computer game developed by 3D Realms and released on May 13, 1997 by GT Interactive. Shadow Warrior was developed using Ken Silverman's Build engine and improved on 3D Realms' previous Build engine game, Duke Nukem 3D...
source was released on April 1, 2005, and JonoF released a port of it on April 2, 2005. However, he admitted that he had access to the Shadow Warrior source code about a week before its release.
The source code of Witchaven
Witchaven
Witchaven is a fantasy computer game developed by Capstone Software and released by Intracorp Entertainment in . It was followed by the sequel named Witchaven II: Blood Vengeance in 1996.-Story:...
, Witchaven II
Witchaven II
Witchaven II: Blood Vengeance is the sequel to the fantasy first-person shooter video game Witchaven, created and released in 1996 by Capstone Software. It was Capstone's last proprietary game release before their parent company Intracorp went bankrupt....
, Tekwar and Corridor 8 have also surfaced. The legal status of these, however, is unclear.