OGRE

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OGRE

Developed by	The OGRE Team
Latest release	1.4.8 (Eihort) / 10 May 2008
Platform	Cross-platform
Genre	3D graphics engine
License	GNU Lesser General Public License
Website	http://www.ogre3d.org/

OGRE (Object-Oriented Graphics Rendering Engine) is a scene-oriented, flexible 3D rendering engine (as opposed to a game engine) written in C++ designed to make it easier and intuitive for developers to produce applications utilising hardware-accelerated 3D graphics. The class library abstracts the details of using the underlying system libraries like Direct3D and OpenGL and provides an interface based on world objects and other high level classes.

OGRE has a very active community, and was Sourceforge.net's project of the month in March 2005.^[1] It has been used in some commercial games like Ankh and Pacific Storm.

1.0.0 ("Azathoth") was released in February 2005. The current release in the 1.x.y series is 1.4.8 ("Eihort"), released in May 2008. Released under the terms of the GNU Lesser General Public License, the engine is free software.

1 General Information
2 Features
3 Google Summer of Code 2006
4 Major version naming
5 History
6 OGRE ports and wrappers
7 Projects using Ogre
- 7.1 Open source
- 7.2 Commercial
8 See also
9 External links
10 References

[edit] General Information

As its name states, OGRE is "just" a rendering engine. As such, its main purpose is to provide a general solution for graphics rendering. Though it also comes with other facilities (vector and matrix classes, memory handling, etc.), they are considered supplemental. It is not an all-in-one solution in terms of game development or simulation as it doesn't provide audio or physics support, for instance.

Generally, this is thought of as the main drawback of OGRE, but it could also be seen as a feature of the engine. The choice of OGRE as a graphics engine allows developers the freedom to use whatever physics, input, audio and other libraries they want and allows the OGRE development team to focus on graphics rather than distribute their efforts amongst several systems. OGRE explicitly supports the OIS, SDL and CEGUI libraries, and includes the Cg toolkit.

Currently OGRE is published under a dual license (one being LGPL, the other one called OGRE Unrestricted License (OUL)), to make it possible to be chosen for console development as well, because most of the publishers reject using free/open-source software in that particular market.

[edit] Features

OGRE has an object oriented design with a plugin architecture that allows easy addition of features, thus making it highly modular.

OGRE is a scene graph based engine, with support for a wide variety of scene managers, most notably octree, BSP and a Paging Landscape scene manager, along with a beta-stage portal-based scene manager under ongoing development.

OGRE is fully multi-platform, with OpenGL and Direct3D support. It can render the same content on different platforms without the content creator having to take into consideration the different capabilities of each platform. This reduces the complexity of deploying a game on multiple systems. Currently pre-compiled binaries exist for Linux, Mac OS X, and all major versions of Windows.

OGRE also supports Vertex and Fragment programs along with custom shaders written in GLSL, HLSL, Cg and assembler.

The landscape scene manager has support for Progressive LOD, which can be automatically or manually created.

The animation engine has full support for hardware weighted multiple bone skinning, which can be fixed across several poses for full pose mixing.

OGRE also has a compositing manager with a scripting language and full screen postprocessing for effects such as HDR, blooming, saturation, brightness, blurring and noise. A particle system with extensible rendering and customizable effectors and emitters.

The libraries also feature memory debugging and loading resources from archives.

There are content exporter tools available for most 3D modelers around including 3D Studio Max, Maya, Blender, LightWave, Milkshape, Sketchup and more.

A full overview of the features provided by OGRE can be found here.

[edit] Google Summer of Code 2006

OGRE got 6 slots in Google Summer of Code 2006 to enhance the existing engine and add new features to it. These entries were:

Tool for one-step solution for artists
RmOgreExporter (v2), FxOgreExporter
Instancing, Crowd Rendering
Extending, Demo-ing, and Documenting the Shadow Mapping System
Scene Management
Billboard Clouds

[edit] Major version naming

The version branch names, Hastur for 0.15.x, Azathoth for 1.0.x, Dagon for 1.1.x and 1.2.x, Eihort for 1.3.x and 1.4.x, Shoggoth for 1.5.x and 1.6.x, have been named after members of an ancient race of fearsome deities called the Great Old Ones in the Cthulhu mythology of H. P. Lovecraft.

[edit] History

A brief history of OGRE, and its milestones:

Around 1999: Sinbad realises that his 'DIMClass' project, a project to make an easy to use object-oriented Direct3D library, has become so abstracted that it really doesn't need to be based on Direct3D any more. Begins planning a more ambitious library which could be API and platform independent.
February 25, 2000: Sourceforge project registered, OGRE name coined. No development starts due to other commitments but much pondering occurs.
February 2005: Ogre v1.0.0 "Azathoth" Final Released - resource system overhaul, hardware pixel buffers, HDR, CEGui, XSI exporter
March 2005: Ogre is 'Project of the Month' on Sourceforge
November 4, 2005: Ankh is released as the first commercial product using Ogre
May 7, 2006: Ogre 1.2 "Dagon" is officially released
March 25, 2007: Ogre 1.4 "Eihort" is officially released

[edit] OGRE ports and wrappers

There exist a number of OGRE bindings to other languages and frameworks including Perl, PureBasic, PyOgre for Python, Ogre.rb for Ruby, Ogre4j for Java and OgreDotNet and MOGRE for .NET.

Alternatively, there's also the Axiom Engine available for C# and other .NET languages, which, instead of wrapping OGRE, tries to implement the same/similar APIs and features in C#.