Game Engine	Level Editor	Model Editor

Game Engine Summary

The Retribution Engine has been designed for first person action games on 3D accelerated PCs running Windows 9x/Me and NT4/2000/XP. It is capable of seamless transitions between indoor and outdoor environments. Indoor areas utilise a volume-based visibility system that removes the need for bsp processing. The outdoor areas are rendered using a quad-tree terrain engine with static level of detail control. The engine is open source (GPL license) and the included games are freeware.

Tools

A tool set is available for the game engine. This includes a level editor and a model editor. Model design is supported by the wide range of md2 editors that are available. The tool set was released to allow people to develop their own levels and space is available in the download section of this site for submitted levels.

3D Graphics

The game engine makes full use of the OpenGL API and so can take advantage of hardware accelerated transformation and lighting. All model lighting and dynamic lighting is provided using OpenGL light sources.

Sound

The game engine supports 3D sound effects and music using the OpenAL API.

Textures and Light Maps

From the start, the engine has been designed to use true-colour (32bit) textures. Textures can be any size supported by OpenGL hardware and are mipmapped using trilinear filtering. Lightmaps are also generated using 32bit textures and so support highly realistic coloured lighting effects. The lighting code automatically generates diffuse and specular lightmaps depending on the strength of applicable light sources.

Special Effects

The game engine supports a wide range of effects:

• Particle Effects
• Shaders
• Glow Maps
• Volumetric Fog
• Volumetric Explosions
• Stencil Shadows
• Chrome Maps
• Weather Effects (Rain and Snow)
• Damage Decals

Scripting

The engine supports powerful scripting features that allow complex sequences, scripted AI and cinematic cut-scenes to be generated at any point in a level. The scripted sequences are created using simple dialogs and so there is no requirement to learn a scripting language.

Models

The game engine provides extensive support for models. The models are complex 3D objects that are of a hierarchical tree construction, i.e. child objects are oriented relative to their parent and in turn can be parents to lower order child objects. Parts can be constructed from standard shapes (e.g. spheres) or meshes imported from .x or .md2 files. Animated md2 models are supported.

Weapons

The game engine supports generic weapon types that can be customised to form a wide arsenal of weapons. Current generic types are melee (e.g. fist), projectile (e.g. laser blaster), exploding projectile (e.g. rocket launcher), instant hit (e.g. pistol, machine gun), beam (e.g. rail gun), grenade and shotgun.