Retribution engine

The Retribution Engine is written by Andrew Gardner et al. and the editing tools were written by Paul Moxon. The engine is open source and is distributed under the GPL license. It is designed to run onWindows and uses OpenGL for rendering and DirectSound for 3D sound effects. The install package includes a game launcher, the game engine, a level editor, a model editor, an episode editor and comprehensive documentation.

• Game Launcher – this program scans the game directory for any games or levels, lists them and allows them to be launched in the game engine. It also allows various game engine parameters such as screen resolution to be configured.
• Game Engine – the game engine program is supplied with a range of textures, models and sounds that can be used to create freeware levels. It has been designed to be highly customisable without the need for programming knowledge.
• Level Editor – this powerful 3D design program allows complete worlds to be designed and populated with rooms, terrain, models, entities, etc.
• Model Editor – this program allows models in established industry formats to be imported and saved in a form that the game engine can understand and use. It also provides facilities to create textured models using a range of standard 3D shapes.
• Episode Editor – this program allows the designer to give a more individual and customised look to their levels.

Work on the Retribution Engine was begun by Andrew Gardner in 1997, inspired by games such as Doom and Quake and also John Bradley’s ‘Tumbling Tie-Fighter’ demo program. The original aim was to create a game titled Corridors of Power. The first public release of the game occurred in March 1999 and consisted of a simple two-level demo of the game. The game and engine were regularly updated and generated much interest. The biggest comment was that game designers would like to use the engine to make their own levels and so Paul Moxon joined the project to develop a level editor in October 2000.From this moment, the work became two related projects. Work continued on Corridors of Power and ran in parallel to continued development of the Retribution Engine. April 2001 saw the first public release of the tools and so allowed others to begin work on their own levels.By August 2002 Corridors of Power was just another mod for the Retribution Engine. John Eriksson and Tom Methven joined the team and began development of the game ‘Dreamworld’ which eventually became ‘Sinister’. Gunrock was also in the process of developing several levels, two of which were ultimately released.In August 2003 Corridors of Power was completed. From this time the official name of the project became the Retribution Engine and work concentrated on the development of the engine and tools while existing designers and new ones such as MitaMAN continued to develop new levels.In December 2006 the project hit a number of difficulties and development ceased. But in June 2007 the engine was reborn as an open source project and with the hope that development might continue with the help of the open source community.

The Retribution Engine is written to take full advantage of OpenGL accelerated transformation and lighting and supports high quality 32bit textures and lightmaps. It also makes full use of the DirectSound API to create realistic 3D sound effects. The use of a volume-based visibility system in conjunction with a static quad-tree terrain engine allows seamless transitions between indoor and outdoor areas.The scripting system is dialog driven and so doesn’t require the designer to use a custom scripting language. This eases the learning curve and makes it possible to quickly create powerful scripted sequences.The innovative weapon system uses generic types to speed and ease development. All the designer has to do is pick a generic type and then customise it in order to create a weapon. This system has allowed the development of over twenty distinct weapons thus far.The engine features support for industry standard .x and .md2 model formats. Models can have various effects applied including shaders, glow maps and chrome maps.The engine also supports various special effects including:

• Particle effects
• Volumetric fog
• Volumetric explosions
• Stencil shadows
• Weather effects (rain and snow)
• Damage decals