osg各个命名空间的细节描述



基于osg3.0.0参考手册，本人翻译，如有错误或翻译不当敬请指出。

osgDB Namespace Reference

Detailed Description

The osgDB library provides support for reading and writing scene graphs, providing a plugin framework and file utility classes.

The plugin framework in centered around the osgDB::Registry, and allows plugins which provide specific file format support to be dynamically loaded on demand. 

细节描述

osgDB库提供对读写场景图形的支持，提供一个插件框架和一些使用的文件类。

插件框架以osgDB：Registry为中心，允许插件提供特殊文件格式的支持以便能够按照要求动态加载。

osgViewer Namespace Reference

Detailed Description

The osgViewer library provides high level viewer functionality designed to make it easier to write a range of different types of viewers, from viewers embedded in existing windows via SimpleViewer, through to highly scalable and flexible Viewer and Composite classes.

A set of event handlers add functionality to these viewers so that you can rapidly compose the viewer functionality tailored to your needs. Finally the viewer classes can be adapted to work with a range of different window toolkit API's via GraphicsWindow implementations, with native Win32, X11 and Carbon implementations on Windows, Unices and OSX respectively, and other window toolkits such as WxWidgets, Qt etc. 

细节描述

osgViewer库提供高水平的查看功能旨在使描绘一系列不同类型的查看器更简单，

使查看器能够插入窗口中已存在的简单查看器中，是一个高扩展性和灵活性的综合类。

一组事件处理程序增加功能到这些查看器中，使得能够迅速构建你想要的查看器功能。

最后，查看器的那些类可以适合与一系列的窗口API一起实现，例如win32,x11和Carbon在windows，unix,ios上分别实现，还有其他的窗口

工具包比如WxWidgets,Qt等。

osg Namespace Reference

Detailed Description

The core osg library provides the basic scene graph classes such as Nodes, State and Drawables, and maths and general helper classes. 

osg核心库提供基础的图形类，例如Nodes类，State类和Drawables类，maths类以及一些常规的帮助类。

osgAnimation Namespace Reference

Detailed Description

The osgAnimation library provides general purpose utility classes for animation. 

osgAnimation库提供一般目的的动画实用类。

osgFX Namespace Reference

Detailed Description

The osgFX library is a NodeKit that extends the core scene graph to provide a special effects framework.

osgFX's framework allows multiple rendering techniques to be provide for each effect, thereby provide the use appropriate rendering techniques for each different class of graphics hardware, i.e. support for both modern programmable graphics hardware and still have standard OpenGL 1.1 support as a fallback. 

osgFX库是一个结点工具包用来扩展osg核心库，提供一个特效框架。

osgFX框架允许一个效果用多种渲染技术实现，因此，对于不同硬件利用不同的类提供不同的渲染技术，支持

现代可编程图形硬件和标准稳定版的OpenGL1.1。

osgGA Namespace Reference

Detailed Description

The 'GA' in osgGA stands for 'GUI Abstraction'; the osgGA namespace provides facilities to help developers write the glue to allow the osg to work with varying window systems.

As a cross-platform, window system-agnostic class library, the OpenSceneGraph has no direct ties to any given windowing environment. Viewers, however, must at some level interact with a window system - where Window system may refer to a windowing API, e.g. GLUT, Qt, FLTK, MFC, ...

There is much commonality in the implementation of Viewers for varying windowing environments. E.g. most Viewers will update a Camera position in response to a mouse event, and may request that a timer be started as a result of a model being 'spun'.

The purpose of the osgGA namespace is to centralise the common areas of this functionality. The viewer writer needs then only write a GUIEventAdapter, a GUIActionAdapter, and assemble a collection of GUIEventHandlers as appropriate for the viewer.

Events from the windowing environment are adpated, and then fed into the GUIEventHandlers. The GUIEventHandlers analyse and take action, and make requests of the windowing environemnt via the GUIActionAdapter. The viewer writer should then honour these requests, translating them into calls to the windowing API. 

osgGA中的GA代表GUI Abstraction，osgGA命名空间提供设施，使开发者能够使用osg和不同的窗口系统一起工作。

作为一个跨平台，跨不同窗口系统的类库，osg没有与任何的窗口环境任何的直接环境。然而查看器必须与窗口系统有所交互--

就是窗口系统所提供的API，例如GLUT,Qt,FLTK,MFC等。。。

对于不同的窗口环境来讲，查看器的实现有很多共性，例如，大多数的视口会通过鼠标响应时间来更新相机。

也或者响应一个 计时器来开始对一个模型“旋转“。

osgGA命名空间的目的在于把这些功能的共同点集中起来。视口writer只需要写一个GUIEventAdapter,一个GUIActionAdapter，并且组合一个

GUIEventHnaders的集合来配合视口。

窗口环境下的事件被适配后送入GUIEventHandlers.GUIEventHandlers分析并作出响应。

视口writer应该遵循这些要求，翻译到响应的API中去。

osgManipulator Namespace Reference

Detailed Description

The osgManipulator library is a NodeKit that extends the core scene graph to support 3D interactive manipulators. 

osgManipulator库是一个结点工具包用来扩充osg核心库对3D交互操作器的支持。

osgParticle Namespace Reference

Detailed Description

The osgParticle library is a NodeKit that extends the core scene graph to support particle effects. 

osgParticle库是一个结点工具包用来扩充osg核心库对粒子效果的支持。

osgQt Namespace Reference

Detailed Description

The osgQt utility library provides various classes to aid the integration of OpenSceneGraph and Qt. 

osgQt实用库用来提供各种各样的类来提供对osg和Qt融合的帮助。

osgShadow Namespace Reference

Detailed Description

The osgShadow library is a NodeKit that extends the core scene graph to add support for a range of shadow techniques. 

osgShadow库是一个结点工具包用来扩展osg核心库对于增加一系列阴影技术的支持。

osgSim Namespace Reference

Detailed Description

The osgSim library is a NodeKit that extends the core scene graph to support nodes and drawables that specific to the visual simulation, such a navigational light point support and OpenFlight style degrees of freedom transform. 

osgSim库是一个结点工具包用来扩充osg核心库对于结点和画板对于特定数据模拟的支持，像一个导航灯支持或者OpenFlight风格角度的自由转换。

osgTerrain Namespace Reference

Detailed Description

The osgTerrain library is a NodeKit that provides geospecifc terrain rendering support. 

osgTerrain库是一个结点工具吧来 提供物理地形渲染支持。

osgText Namespace Reference

Detailed Description

The osgText library is a NodeKit that extends the core scene graph to support high quality text. 

osgText库是一个结点工具包用来扩展osg核心库对高质量文本的支持。

osgUtil Namespace Reference

Detailed Description

The osgUtil library provides general purpose utility classes such as update, cull and draw traverses, scene graph operators such a scene graph optimisation, tri stripping, and tessellation. 

osgUtil库提供常规的实用类，例如更新，剔除和绘制遍历，场景图形操作比如一个场景图形的优化，三角形撤销和纹理。

osgVolume Namespace Reference

Detailed Description

The osgVolume library is a NodeKit that extends the core scene graph to support volume rendering. 

osgVolume库是一个结点工具包用来扩展osg核心库对于大量渲染的支持。

osgWidget Namespace Reference

Detailed Description

The osgWidget library is a NodeKit that extends the core scene graph to support a 2D (and eventually 3D) GUI widget set. 

osgWidght库是一个结点工具包，用来扩展osg核心库对于场景图形对于2D/3D图形用户接口窗口小部件集的支持。