A framework for distributed 3D graphics applications based on compression and streaming. (Un cadre unificateur pour des applications graphiques 3D, basé sur la compression et la diffusion)

The first computers were very expensive and large in size. Therefore the only economic way to use them was remote computing: connect to the central computer by a light terminal. With the development of Integrated Circuits the components started to be cheaper and smaller, therefore the terminals started to support computing. Their processing power is currently enough for many applications, however when more processing power is needed, there is still the possibility of remote computing through the Internet or dedicated networks. With the arrival of mobile terminals a new iteration of remote computing is happening. By nature the mobile terminals are connected and since their processing power may not be enough for many applications, they may be helped by a remote, more powerful computer. Therefore, the main goal of this chapter is to introduce the remote computing paradigm for multimedia applications. It will focus on a part of the multimedia application, i.e. 3D graphics applications, and present the state of the art in this field. The first part of this chapter introduces the elements of the modern remote computing with focus on the general architectures that are used. Next it reviews the current state of the art for providing 3D graphics content in a client-server configuration. Different architectures are compared, starting from systems implementing all the operation for 3D graphics rendering on the client to distributed systems implementing the rendering on the server and streaming the video to the client. The analysis includes architecture intended for different types of terminals, from powerful computers like PCs to light terminals like mobile phones and PDAs. The second part of this chapter presents some of the most used standardized multimedia scene formats, including VRML, X3D, SMIL, SVG, COLLADA and MPEG-4. The standards are analyzed focusing on their capabilities in terms of supported features, compression and streaming support. Then it is shown why MPEG-4 was selected as the most appropriate format and further describes the MPEG-4 standard with respect to its streaming and synchronization capabilities. Furthermore, the BIFS format is described exposing its compression and scene update capabilities. te l-0 07 11 80 5, v er si on 1 25 J un 2 01 2