1487 U Use of Semantics to Manage 3D Scenes in Web Platforms Christophe Cruz Université de Bourgogne, France Christophe Nicolle Université de Bourgogne, France Copyright © 2009, IGI Global, distributing in print or electronic forms without written permission of IGI Global is prohibited. internet and 3d sCenes Computer graphics have widely spread out into vari- ous computer applications. After the early wire-frame computer generated images of the 1960s, spatial representation of objects improved in the 1970s with Boundary Representation (B-Rep) modeling, Construc- tive Solid Geometry (CSG) objects, and free-form surfaces. Realistic rendering in the 1990s, taking into account sophisticated dynamic interactions (between objects or between objects and human actors, physi- cal interactions with light, and so on) now make 3D- scenes much better than simple 3D representations of the real world. Indeed, they are a way to conceive products (industrial products, art products, and so on) and to modify them over time, either interactively or by simulation of physical phenomena (Faux & Pratt, 1979; Foley, Van Dam, Feiner, & Hughes, 1990; Kim, Huang, & Kim, 2002). Large amounts of data can be generated from such variety of 3D-models. Because there is a wide range of models corresponding to various areas of applica- tions (metallurgy, chemistry, seismology, architecture, arts and media, and so on) (DIS 3D Databases, 2004; Pittarello & De Faveri, 2006; SketchUp from Google, 2006), data representations vary greatly. Archiving these large amounts of information most often remains a simple storage of representations of 3D-scenes (3D images). To our knowledge, there is no effcient way to manipulate, or archive, extract, and modify scenes together with their components. These components may include geometric objects or primitives that compose scenes (3D-geometry and material aspects), geomet- rics transformations to compose primitives objects, or observation conditions (cameras, lights, and so on). Diffculties arise less in creating 3D-scenes, rather than in the interactive reuse of these scenes, particularly by database queries, such as via Internet. Managing 3D- scenes (e.g., querying a database of architectural scenes by the content, modifying given parameters on a large scale, or performing statistics) remains diffcult. This implies that DBMS should use the data structures of the 3D-scene models. Unfortunately, such data structures are often of dif- ferent or exclusive standards. Indeed, many “standards” exist in computer graphics. They are often denoted by extensions of data fles. Let us mention, as examples, 3dmf (Apple’s Quickdraw 3D), 3ds (Autodesk’s 3D- Studio), dxf (AutoDesk’s AutoCAD), ft (Multigen’s ModelGen), iv ( Silicon Graphics’ Inventor ), obj ( Wavefront/Alias ), and so on. Many standardization attempts strive to reduce this multiplicity of various formats. In particular, there is Standard for the Ex- change of Product model data (STEP) (Fowler, 1995), an international standard for computer representation and exchange of products data. Its goal is to describe data bound to a product as long as it evolves, indepen- dently of any particular computer system. It allows fle exchanges, but also provides a basis for implementing and sharing product databases. Merging 3D informa- tion and textual information allows the defnition of the project’s mock-up. As a matter of fact, 3D information describes CAD objects of the project and textual added information gives semantic information on geometries. The main issues are the sharing and the exchange of the digital mock-up. The next section explains how we use a digital mock-up to create an information system with the help of the semantic included in geometric information. Information is exchanged and shared through a Web Platform. baCKgroUnd With the emergence of new powerful computers, the 3D models created by computer-aided design tools are