常见的3D引擎有：Unreal,Quake,Lithtech,OGRE,Nebula,Irrlicht,Truevision3D...等，其中开源免费的有：orge,irrlicht,fly3d, NeoEngine, revolution3d, Nebula2，Genesis3d等。OGRE 在免费、开源的引擎中评价最高，一个原因是作为一个图形渲染引擎，它支持的图形特性最多，所以渲染质量也不错；另一个原因是设计模式的清晰；另外，速度也不错。OGRE 将专注于向一个纯粹的、然而富于协作和扩展性的图形引擎发展，这得益于它的庞大的社群支持，使得很多事情可以通过外挂一些更专业的引擎来实现，物理引擎使用 ODE 、 Tokamak 、 NovodeX ，网络引擎使用 openTNL 、 RakNet 、 eNet ，声音引擎使用 FMod 、 OpenAL ，以及界面引擎使用 CEGUI 。
Standard
OGRE
IrrLicht
Truevision3D
General
Type
Only rendering engine
Game engine
Include TV3DEngine,TV3DMedia,TV3DNet……
Languages
Written in pure C++, totally object orientated.
Written in pure C++, totally object orientated.
Written in C++ and VB6 with DirectX8.1
License
LGPL
zlib/libpng License(totally free)
· Free TV3DSDK
· Registered Developer License
· group or site licenses
Develop platforms
· C++
· .NET
· C++
· .NET language binding
VB/VC++/DELPHI/
C#/vb.net
Platforms
Windows
ü Support
ü Support
ü Support
Linux
ü Support
ü Support
MacOS
ü Support
ü Support
3D API
Direct3D
ü Support
ü Support
ü Support
OpenGL
ü Support
ü Support
Other
· The Irrlicht Engine software renderer.
· The Apfelbaum Software Renderer
Architecture
Extensibility
· Extensible example framework
· Flexible plugin architecture allows engine to be extended without recompilation
· Use some other professional engines to achieve other features
Scripting
Materials & Textures
Materials
· Powerful material declaration language
· Multiple material
· Material LOD
· Multi-texture and multi-pass blending
· Projective texturing
· Textures can be provided and updated in real-time by plugins
· Provide common built in materials based on fixed function pipeline or programmable pipeline
· add new materials to Irrlicht at runtime, without the need of modifying/recompiling the engine
Textures and Mapping
自动产生MipMap；
自动调整纹理大小以满足硬件需求。
支持可程序控制的纹理坐标生成和转换。
· Bump mapping
· Parallax mapping
· Light maps
· Sphere mapping
DOT3 Bump mapping
没有提供多层纹理和混合模式
Shaders
· Supports vertex and fragment programs, both written in assembler, and in Cg, DirectX9 HLSL, or GLSL
· Support many commonly bound constant parameters like worldview matrices, light state information, object space eye position etc
· Pixel and Vertex Shaders 1.1 to 3.0
· ARB Fragment and Vertex Programs
· HLSL
· GLSL
· Hardware Vertex Shaders
· HLSL
Scene Management
General
· Highly customizable, flexible scene management, not tied to any single scene type.
· Hierarchical scene graph; nodes allow objects to be attached to each other and follow each others movements, articulated structures etc
· Scene querying
· Using a hierarchical scene graph, can mix indoor and outdoor scene seamless together
· Extensible hierarchical scene management
BSP Support
BSP 场景的天空穹、粒子特效、高级材质属性，乃至 BSP 的空间分割规则都会被正确识别、自动实现
· 对 BSP 的特性支持比较贫乏
对 BSP 的读取存在 BUG
Other
Special effects
Particle System
· easily extensible emitters, affectors and renderers
· can be defined in text scripts for adjusting in real-time
· particle pooling
· Customizeable Particle systems for snow, smoke, fire, ...
Atmospheric effects like fog, cloud, sky (box and sphere), stars.
Light & Shadow
当前支持三种阴影：调整纹理阴影,调整模版阴影,附加模板阴影。不支持软阴影
Multiple shadow rendering techniques,
· Dynamic lights
· Dynamic shadows using the stencil buffer
· Optimized dynamic stencil shadows
· DirectX Hardware Lighting
Other
· Support for skyboxes, skyplanes and skydomes
· Billboarding for sprite graphics
· Transparent objects automatically managed
· Realistic water surfaces
· Billboards
· Transparent objects
· Skyboxes
· Fog
· Texture animation
Billboard
Character Animation
· Skeletal animation
· blending of multiple animations
· variable bone weight skinning
· hardware-accelerated skinning
· Morph target animation:
· Skeletal animation
· Skeleton based, Key frame based, morph based animations
· Animations that can be enhanced by bone attaching or custom bone rotations.
Supported Formats
textures file formats
· PNG, JPEG, TGA, BMP or DDS
· 1D textures, volumetric textures, cubemaps and compressed textures (DXT/S3TC)
· PSD,JPG,PNG,TGA,BMP,PCX
mesh file formats
Milkshape3D, 3D Studio Max, Maya, Blender and Wings3D
· 3DS,OBJ,CSM,DAE,DMF,OCT,X,MS3D,MY3D,LMTS,BSP,MD2
3DS, X, MDL, MD2, MD3
Document
Great number of users and well documented.
well documented API with lots of examples and tutorials.
Other
GUI
2D Drawing
XML
ü Support
XML Converter: convert efficient runtime binary formats to/from XML for interchange or editing
ü Support
快速的XML分析器
Web Site
http://www.ogre3d.org
http://irrlicht.sourceforge.net
http://www.truevision3d.com
