Wolfenstein 3D engine
| Developer(s) | id Software |
|---|---|
| Written in | C, x86 assembly language |
| Type | Game engine |
The Wolfenstein 3D engine is the engine that powers Wolfenstein 3D. The biggest part of the engine is programmed by John Carmack. It is written in C and x86 assembly language. It features graphics (ray casting), sound (WAV and IMF), player physics and game control.
Contents |
[edit] Features and limitations
To render the walls in pseudo-3D, the game uses ray casting. This technique emits one ray for each column of pixels, checks if it intersects a wall, and draws textures on the screen accordingly, creating a one dimensional depth buffer against which to clip the scaled sprites that represent enemies, powerups, and props.
Before Wolfenstein 3D, the technology had already been used by id Software in 1991 to create Hovertank 3D and Catacomb 3-D for Softdisk. Other games using the Wolfenstein 3D game engine or derivatives of it were also produced, including Blake Stone, Corridor 7: Alien Invasion, Operation Body Count, Super 3D Noah's Ark, Rise of the Triad, and Hellraiser, an unreleased Color Dreams game planned for the PC and the Nintendo Entertainment System.
According to id Software programmer John Carmack, the game's engine was inspired by a technology demo of Looking Glass Studios'/Origin's first-person role-playing video game, Ultima Underworld: The Stygian Abyss from 1991. Carmack claimed he could make a faster renderer.[1] In this he was successful. The Wolfenstein engine lacks many features present in the Underworld engine, such as ceiling or floor height changes, sloped floors and lighting, but it ran well on relatively weak hardware.
The secret behind engine's performance is vertical scanline scaling algorithm. Unlike later engines and hardware rasterizers, the texture coordinate for the pixel is not calculated at runtime. Instead, a fixed set of several hundreds rendering functions is generated during game startup (or viewport size change) where all memory offsets are fixed. To keep the number of these procedures small, height is quantized, which can be easily seen when player is close to the wall, but not looking at it at a right angle.
Features include:
Limitations of the engine include:
- Looking and/or moving up and down is not supported.
- It does not support differences in brightness of the lights.
- It does not support differences in geometrical height.
"Holo-walls" are walls created by mapmakers using a glitch in the PC version's engine. They are walls that the player can walk through, and are used in some total conversions to simulate windows that players can climb through, and hedges that players can walk through. One way of creating holo-walls is to place a dead guard in a wall.
[edit] Games Using the Wolfenstein 3D Engine
 |
This section may be confusing or unclear to readers. In particular, it does not state whether all games listed in it use the Wolfenstein 3D engine or not, or if the predecessors also use the same engine; if they do not, maybe they should be listed in another section. Please help clarify the section; suggestions may be found on the talk page. (August 2011) |
- Wolfenstein 3D
- Spear of Destiny
- Blake Stone: Aliens of Gold
- Blake Stone: Planet Strike
- Operation Body Count
- Corridor 7
- Super 3D Noah's Ark
Rise of the Triad uses a very heavily modified version of Wolfenstein 3D engine, which adds numerous new features.
[edit] Predecessors
A few 3D games used the technology developed by Carmack before Wolfenstein 3D.
[edit] See also
[edit] External links
- Source code at id Software's FTP server
- Engine source code and compiling instructions
- DieHard Wolfers Forum - Forum about Wolf3D and programming
[edit] References
- ^ Mallinson, Paul. (2002). [Interview with Paul Neureth and Doug Church, developers of Ultima Underworld]. Games that changed the world: Ultima Underworld, Computer and Video Games site.
|
|||||||||||||||||
