计算机专业英语（第二版） -孙建忠 Chapter13.pptVIP

Computer English Chapter 13 Virtual Reality 求职英语简介 求职英语简介 求职英语简介 求职英语简介 求职英语简介 求职英语简介 求职英语简介 求职英语简介 13.3.3 Scope The VRML specification defines a file format that integrates 3D graphics and multimedia. Conceptually, each VRML file is a 3D time-based space that contains graphic and aural objects that can be dynamically modified through a variety of mechanisms. VRML defines a primary set of objects and mechanisms that encourage composition, encapsulation, and extension. VRML能表示静态及动态的三维和多媒体对象，并通过超链接连到诸如文本、声音、电影及图像等其它媒体。VRML浏览器，同制作VRML文件的制作工具一样，广泛应用于许多不同的平台上。 13.3 About VRML The semantics of VRML describe an abstract functional behavior of time-based, interactive 3D, multimedia worlds. VRML does not define physical devices or any other implementation-dependent concepts (e.g., screen resolution and input devices). VRML is intended for a wide variety of devices and applications, and provides wide latitude in interpretation and implementation of the functionality. For example, VRML does not assume the existence of a mouse or 2D display device. VRML的语义描述了一个抽象的时间依赖的、交互性3维的功能行为。VRML并不定义一个具体的设备或任何依赖它实现的概念（比如：屏幕分辨率和输入设备）。VRML适用于大量的设备和应用程序，并且提供了一个对功能加以解释和实现的广泛空间。比如：VRML并不认为有鼠标或2维显示设备的存在。 13.3 About VRML 13.3.4 Each VRML file: 1. implicitly establishes a world coordinate space for all objects defined in the file, as well as all objects recursively included by the file; 2. explicitly defines and composes a set of 3D and multimedia objects; 3. can specify hyperlinks to other files and applications; 4. can define object behaviors. 1. 为文件中的所有对象建立了一个世界坐标系，也包括在文件中递归包含的所有对象。 2. 明确定义并构成一个3D和多媒体对象的集合。 3. 可定义超链接与其它文件和应用程序相连。 4. 可定义对象的行为。 13.3 About VRML An important characteristic of VRML files is the ability to compose files together through inclusion and to relate files together through hyperlinking. For example, consider the file earth.wrl which specifies a world that contains a sphere representing the earth. This file may also contain references to a variety of other