转:典型开源3D引擎分类比较

常见的3D引擎有：Unreal、Quake、Lithtech、OGRE、Nebula、Irrlicht、Truevision3D...

其中开源免费的有：OGRE、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 IncludeTV3DEngine,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		Support	Support	Support
Linux		Support	Support
MacOS		Support	Support
3D API
Direct3D		Support	Support	Support
OpenGL		Support	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.sixxs.org	http://irrlicht.sourceforge.net.sixxs.org	http://www.truevision3d.com.sixxs.org