May 17, 2005
Transforming Technologies for Mobile 3D Computing
Whereas VRML is a monolithic all-or-nothing standard, meaning a VRML software product must implement all of the features and capabilities defined by the VRML specification in order to be considered compliant with the standard, X3D supports the concept of components and profiles that make it infinitely more flexible and customizable than VRML by comparison. Components and profiles, in turn, enable X3D to scale gracefully from low-powered mobile devices to extremely powerful scientific workstations and all stops in between.
X3D Components: An X3D component is a set of related functionality that consists of various X3D objects and services. Although a component is usually a collection of X3D nodes, it can also include encodings, API services, or other features. X3D revolves around a Core component that defines the base functionality (such as the abstract base node type, field types, event model, and routing) required for the X3D run-time system. In short, the Core component provides the minimum functionality required by a compliant X3D implementation. In addition, X3D defines standard components for a variety of capabilities, including Geometry, Appearance, Time, Lighting, Sound, Navigation, Scripting, Text, Texturing, NURBS, Humanoid animation (H-Anim), and more. Advanced components to support features such as subdivision surfaces, shaders and other sophisticated 3D capabilities are also under development. Vendors can implement any of the pre-defined standard components or define their own for private use. They can also publicly register their proprietary components with the Web3D Consortium.
X3D Profiles: An X3D profile is a named collection of functionality and associated requirements that must be supported in order for an implementation to conform to that profile. Profiles are further defined as a set of components and corresponding support levels, as well as the minimum support criteria for all of the objects contained within that set. The X3D specification specifies the following five profiles:
- Core profile defines the minimal file definitions and capabilities required by X3D
- Interchange profile supports the exchange of X3D content among authoring and publishing systems
- Interactive profile supports delivery of rich graphics and interactive content to potentially lightweight devices
- MPEG-4 interactive profile defines a base point of interoperability with the MPEG-4 streaming media standard and supports lightweight devices
- Immersive profile supports immersive virtual worlds with complete navigational and environmental sensor control
- Full profile supports the complete set of X3D features. Vendors may also define their own profiles, if desired.
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2 VRML and X3D for Mobile Devices
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3 X3D Components and Profiles
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4 Java 2 Micro Edition
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