C4 Engine

Infobox Software
name = C4 Engine

caption =
developer = [http://www.terathon.com/ Terathon Software LLC]
latest_release_version = Version 1.4.10
latest_release_date = July 25, 2008
latest_preview_version = Version 1.4.10
latest_preview_date = July 25, 2008
operating_system = Microsoft Windows Mac OS X Playstation 3
platform = PC, Mac, PlayStation 3
genre = Game Engine
license = Multiple types
website = [http://www.terathon.com/c4engine/ C4 Engine Overview]

The C4 Engine is a computer game engine created by Terathon Software that can be used to develop games for Windows (XP and Vista), Mac OS X (versions 10.4 and 10.5), and the PlayStation 3 game console.

Development

The C4 Engine possesses the unique quality among commercial game engines that it was programmed entirely by one person, computer graphics author Eric Lengyel. [ [http://www.terathon.com/c4engine/index.php C4 Engine home page] .] Although in development sporadically for several years beforehand, the engine was first made available under a commercial license in May, 2005. Since then, C4 has been under continuous development, and approximately 15 updates have been released each year since its debut. [As calculated from the release dates shown in the [http://www.terathon.com/c4engine/notes.php C4 Engine Release Notes] .] Each version of the C4 engine is identified by a build number that is incremented with every new release.

Technology

The architecture of the C4 Engine is that of a layered collection of software components, [ [http://www.terathon.com/c4engine/architecture.php C4 Engine Architecture] .] in which the lowest layers interact with the computer hardware and operating system, and the higher layers provide platform-independent services to the game code. While a considerable portion of the engine is dedicated to 3D rendering, there are also large components dedicated to functionality pertaining to audio, networking, and input devices.

Graphics

Scenes rendered with the C4 Engine use a combination of several different types of light sources and shadowing methods. [ [http://www.terathon.com/wiki/index.php?title=Lights_and_Shadows Lights and Shadows] on the C4 Engine wiki.] The primary method for rendering dynamic shadows is stencil shadow volumes, but the engine also supports shadow mapping for static light sources.

Shaders are created in C4 by specifying a set of material attributes instead of the actual shader code required by the graphics driver. The engine internally generates the necessary shader code for each combination of material and light type that it encounters when rendering a scene. Material attributes can be used to produce effects such as normal mapping, parallax mapping, horizon mapping, and bumpy reflections or refractions.

The engine is capable of rendering a large variety of special effects, including particle systems, procedural fire, electrical effects, volumetric fog, and weather phenomena. [ [http://www.terathon.com/c4engine/features.php C4 Engine Features] .] During a post-processing stage, the engine can also apply full-scene cinematic motion blur to the final image using a technique based on a velocity buffer. [ [http://www.terathon.com/wiki/index.php?title=Motion_Blur Motion Blur] on the C4 Engine wiki.]

Audio

The C4 Engine can play sounds stored in the WAV format using 16-bit mono or stereo sampling, and audio data can be played from memory or streamed from disk. The engine plays sounds using a custom mixer that provides capabilities such as frequency shifting, Doppler effect, reverberation, and atmospheric absorption.

Networking

Multiplayer gameplay in C4 is supported by a two-layer messaging system that uses the UDP protocol to communicate among different computers connected to a game.

Tools

The C4 Engine ships with a number of tools that are essential for the development of a game. Each tool is packaged as a plugin module that exists separately from the engine itself. Many tools make use of the comprehensive graphical user interface system provided by the engine so that a consistent interface is presented to the user across multiple platforms.

World Editor

The World Editor tool, shown in the image to the right, is a 3D content creation application that is typically used to create game environments for use with the C4 Engine. It provides a large set of drawing and manipulation capabilities that are used to construct world geometry as well as many game necessities such as lights, sounds, triggers, and special effects. [ [http://www.terathon.com/wiki/index.php?title=World_Editor_Overview World Editor Overview] on the C4 Engine wiki.]

The World Editor can import scene information through the COLLADA format. This enables the use of content from a large number of digital content creation programs such as Maya or 3D Studio Max.

Script Editor

The World Editor tool includes a graphical script editor designed to be accessible to artists and level designers as well as programmers. The script editor, shown in the image to the right, allows the user to drag various “methods” into a tree representing action dependencies and the order of execution. [ [http://www.terathon.com/wiki/index.php?title=Using_the_Script_Editor Using the Script Editor] on the C4 Engine wiki.]

The engine ships with several standard script methods that perform simple actions such as enabling or disabling a scene node (for example, to turn a light on or off). New script methods can be defined by the game code, and they appear in the script editor as new actions that can be used by a level designer.

Panel Editor

The World Editor tool includes a sub-editor called the “panel editor” that allows the creation of 2D interface panels that can be placed inside a 3D world. The panel editor, shown in the image to the right, lets the user place image items and text items in a panel effect node that is rendered as part of the scene. [ [http://www.terathon.com/wiki/index.php?title=Using_the_Panel_Editor Using the Panel Editor] on the C4 Engine wiki.] Panels can also include a special camera item that displays the scene that is visible to a camera placed anywhere else in the same world.

Interface panels are both dynamic and interactive. The engine provides an extensible set of “mutators” that can be applied to individual panel items to induce various forms of animation such as scrolling, rotation, or color change. A character in a game can interact with a panel by approaching it and clicking the mouse inside interactive items. Script can be attached to such items, causing a sequence of actions to occur when the player activates them.

Licensing

There are four types of commercial licenses available for the C4 Engine. [ [http://www.terathon.com/c4engine/licensing.php C4 Engine Licensing] .] The standard license costs $350 (US) per user and is available to independent developers who do not receive funding from a major publisher. Publisher-funded development studios are required to purchase a professional license.

For the development of applications outside the realm of entertainment, a serious games license is offered. A serious games license for the C4 Engine has been acquired by Lockheed Martin. [http://www.terathon.com/c4engine/news.php C4 Engine News] .]

Lastly, an educational site license is available to institutions that wish to use the C4 Engine for instructional purposes. The C4 Engine has been licensed by Georgia Tech, Worcester Polytechnic Institute, McMaster University, and the University of Kempten. Each license includes the complete source code to the engine, sample games, and tools. All future updates to the engine are included with every license at no additional cost. Products created with the C4 Engine are required to display the “Powered by the C4 Engine” logo.

Games Using C4

The following list names several games that are in development using the C4 Engine. [ [http://www.terathon.com/wiki/index.php?title=Games Games] on the C4 Engine wiki.]

* Ravensword
* Mojave's Edge
* Celestial Sphere
*
* Vortex of Hostility
* Clan Arena
* Illusion of Destiny
* World of Subways

Screenshots

References

External links

* [http://www.terathon.com/c4engine/index.php Official C4 Engine website]
* [http://www.devmaster.net/engines/engine_details.php?id=42 C4 Engine technical details and user reviews]