14.2.1 Design Criteria

　　VRML has been designed to fulfill the following requirements:

　　Authorability

　　Enable the development of computer programs capable of creating, editing, and maintaining VRML files, as well as utomatic translation programs for converting other commonly used 3D file formats into VRML files.

　　14.2.1 设计标准

　　VRML需要满足如下要求：

　　创作性

　　使得应用程序能够建立、编辑、保存VRML文件，也是一个自动 翻译程序，能够将通常使用的3D文件格式转换成VRML文件。

　　l 14.2.1 Design Criteria

　　Composability

　　Provide the ability to use and combine dynamic 3D objects within a VRML world and thus allow re-usability.

　　l Extensibility

　　Provide the ability to add new object types not explicitly defined in VRML.

　　¨重构性

　　¨能够在VRML环境中使用和组合动态3D对象，并允许重用。

　　¨扩展性

　　¨能够加入在VRML中没有明确定义的新的对象类型。

　　l 14.2.1 Design Criteria

　　Implementability

　　Capable of implementation on a wide range of systems.

　　Performance

　　Emphasize scalable, interactive performance on a wide variety of computing platforms.

　　l Scalability

　　Enable arbitrarily large dynamic 3D worlds.

　　适用性

　　能够在各种系统中使用。

　　性能

　　在各种不同的计算机平台上强调可扩展的、交互的性能。

　　可扩展性

　　适于任意大的动态三维世界。

　　l 14.2.2 Characteristics of VRML

　　VRML is capable of representing static and animated dynamic 3D and multimedia objects with hyperlinks to other media such as text, sounds, movies, and images [1]. VRML browsers, as well as authoring tools for the creation of VRML files, are widely available for many different platforms.

　　VRML的特性

　　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。

　　l 14.2.2 Characteristics of VRML

　　VRML supports an extensibility model that allows new dynamic 3D objects to be defined and a registration process that allows application communities to develop interoperable extensions to the base standard. There are mappings between VRML objects and commonly used 3D application programmer interface (API) features.

　　VRML支持扩展模式，即允许创建新的3维动态对象，并允许应用程序组开发在基础模式上加以扩展的可共同操作的文件。在VRML对象和通常使用的应用程序接口特性间有相应的映射。

　　l 14.2.3 Scope

　　The VRML specification defines a file format that integrates 3D graphics and multimedia. Conceptually, each VRML file is a 3D time-based space [3] 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.

　　领域

　　VRML规范定义了一种可将3D图形和多媒体结合起来的文件格式。总体上，每个VRML文件是3维时间依赖空间，包含能够通过不同机制动态修改的图像和音频对象。VRML定义了一个对象的初始集，并允许将对象进行合成、封装和扩充。

[1]  [2]