The limitations of interactive multiuser 3D environments in the WWW

With the emergence and integration of the languages VRML and JAVA, the number of available shared virtual environments in the WWW is increasing. However, due to the slow progress of the VRML language and the lack of conformance to its complete specification by the actual browsers, successful 3D environments face some limitations: from high latency to low presentation quality and small number of users supported. This is further worsened by the restrictive security placed upon applets what prevents the use of more efficient communication models such as multicasting (also limited by the actual network technology of the Internet). This article discusses these limitations and presents the implementation and evaluation of the Shared Virtual Reality Tool (SVRT), which supports the sharing of virtual environments among multiple users through the integration of tools and mechanisms of the WWW. The evaluation shows that latency is, on average, 200 ms-a value considered as acceptable in the literature for loosely synchronized interactive 3D applications.