Friday, April 14, 2006

Scene Managers - Steve and Eddie

OGRE is the brainchild of Steve Streeting, instigator and self-styled "benign dictator of the project.

Steve Streeting is a software developer / manager based on a little rock called Guernsey, an island off the coast of France - a very nice place to live, if a little small and expensive. Despite its location the island is a British crown dependency, although it is politically and economically separate, meaning it is not part of the European Union or the UK, technically.

OGRE does not assume the type of game or demo you want to make. It uses a flexible class hierarchy that allows you to design plug-ins to specialize the scene organization approach you take. (A
is an abstract representation of what is shown in a virtual world.) This enables you to make any kind of game you want—from flight simulator to first-person shooter to 2.5D combat.

  • Scenes may consist of static geometry (such as terrain or building interiors), models (such as trees, chairs, or monsters), light sources that illuminate the scene, and cameras that view the scene.

  • Scenes can have quite different types. An interior scene might be made up of hallways and rooms populated by furniture and artwork. An exterior scene might consist of a terrain of rolling hills, trees, grass waving in the breeze, and a blue sky with moving clouds.

OGRE provides a set of scene managers, each of which is customized to best support a certain kind of scene.

For example, the Binary Space Partition (BSP) Scene Manager handles Quake-type level maps for a first-person shooter type of scene, and the Terrain Scene Manager provides vertex program-based morphing between Levels of Detail and fast high-resolution terrain rendering, which could be used for a flight simulator.

Of course, you can easily transition between any two scene managers to allow a character to move from a realistic outdoor setting into an underground dungeon, for example (see Figure 1).

Figure 1. The view from the lush, animated adventure game Ankh.

Courtesy Victor Volkman

Ogre3D on Mac OS X is explained at


In order to build a game, one needs a visual development window to move elements around. Such a Graphical User Interface (GUI) for Ogre3D is CEGUI.

Crazy Eddie GUI was started by Paul Turner ("CrazyEddie") about two years ago and is currently in it's second major revision, "Mk2". The project supports windows, linux and MacOS.

The library is object orientated, written in C++, and targeted at games developers who should be spending their time creating great games, not building GUI sub-systems!



With the Rendering Engine (OGRE) and the Graphical User Interface (CEGUI) we move onto the Game environment; WorldForge.


WorldForge's mission is to produce the necessary tools and technologies that will allow the creation of graphically rich games of cooperation and socialization. We strive to blur the distinction between player and maker, and wish to establish a positive community environment for current and future free game developers.

Visit their NewBie Guide, it's Fun!:

"Welcome to the idealistic world of Free Software computer game developement! Please leave all excess baggage at the front desk and proceed directly to any one of the fine lecture halls before you. If you're the impatient sort you may wish to skip ahead to the next page. If you are like me however, and like a good story you'll want to grab a soft drink and settle in your most comfortable chair whilst I spin a tale about what happens when people dare to dream."

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