Games: Introduction and Structure

Many algorithms that we have studied in this course apply to games. Actually, a game engine is a software enabling interactive visualization of a set of objects (basically polygonal models and textured triangle meshes) and interaction with them according to a preset script. Find here an Unai Landa's meeting (May 30^th 2007) about structure of a game engine . A game engine must enable the following,

• Interactive navigation in real time, with first person camera

• Objects with behavior, reacting our interaction

• Pre-established object animation (they move, but they are no affected by our interaction)

• Execution of a scipt

• Special Effects

There are some URLs presenting game engines with free software; see Crystal Space and Disney (panda 3d) . Find here a presentation about Crystal Space .

Many of the algorithms are common in games and virtual reality applications. The basic difference consists of that script in games, and additionally a priority on visual quality and special effects over faithful and precision to the original model. From visualization and interaction point of view, in virtual reality we need a high-precision model because we may be interested in deep zooms, appreciate details or take measurements on the model. On the other side, in games we may be more interested in object's behavior and the overall quality using textures. In the following table several algorithms used in VR and games are classified, showing in each case its importance in both applications, and its corresponding chapter in the course program:

Mark "X" means that the techinique is significantly used in that application. Mark "x" means the same, but usage is less intensive.

Some other algorithms used in games, such those regarding special effects, acoustics and sound, artificial intelligence or networking, are out of the scope of this course.