Adapting multiuser 3D virtual environments to heterogeneous devices

摘要

With the growing dissemination and reliability of wireless networks and the emergence of devices with increasing processing and communication power, applications that up to now were restricted to the PCs are being envisaged to run on devices as heterogeneous as wrist clocks, refrigerators with access to the internet, mobile phones, PDAs, set-top-boxes, game consoles etc. Application development for this myriad of devices and networks with different capabilities requires special attention from the software programmers and designers -especially when these applications are shared among multiple users. Application adaptation, which allows a software to react to device and environment resource variations, is an important process to fit the application to a certain device configuration. A large amount of work has focused on the adaptation of multimedia such as text, images, audio and video. Less attention has been given to 3D media adaptation — firstly because of the complexity involved in the 3D application adaptation, and also because true marketing opportunities for 3D applications in heterogeneous devices have just began to emerge. This paper analyses 3D media adaptation as a nonfunctional requirement for 3D multiuser virtual environment applications. An adaptation framework is proposed that can be integrated to the MPEG-4 standard to offer a solution to the adaptation of 3D multiuser virtual environment applications, which can be accessed from heterogeneous devices with different capabilities. The advantages of integrating the framework to the MPEG-4 standard are twofold: it favors the creation of complex applications, with high degree of interaction, such as multiuser 3D collaborative environments; and makes easier to build these applications for heterogeneous devices (from cellular phones to PDAs and set-top-boxes) since MPEG-4 is aimed at small mobile devices and narrowband networks, such as some wireless networks.