| The research that is done in order to develop systems for virtual reality mostly concentrates on the creation of new hardware and applications. These technologies need to be tested in a general context. For this purpose, one usually uses simple software tools that allow fast evaluation. Unfortunately, these tools lack important properties like scalability and generality.; The VEplatform was developed in order to overcome these shortcomings. The VEplatform is an open base platform on which virtual reality applications can be built. The structure is based on active objects that render a flexible and dynamical system. Special attention is paid on software engineering such that the extensibility of the system is obtained.; The VEplatform differs from other systems in different ways. The communication protocols use unicast mechanisms. Although unicast is theoretically not the ideal choice, it proves to be more performant than multicast in practical situations. This is caused by the fact that some synchronisations are not needed any more.; The VEplatform also defines a way to relocate active objects to other hosts in order to retain maximal performance (load-balancing). Especially on slower networks (like the Internet) this can be of great importance.; The VEplatform is not developed for one specific application. Therefore, it can be used within different contexts, without modification of the internal structure. More specifically, VEplatform supports the use of multi-user worlds.; The VEplatform system was tested by building two applications. The first application has a high demand on system resources. It enables different users to visit a virtual world where they can choose products (books in this case) and order them.; A second, totally different application was built in order to test if VEplatform can be adapted easily. This test uses VEplatform to visualise the results of a simulation (virtual life).; The result of both tests prove that the concepts, introduced in this document, really are a good choice and that they are useful in many practical situations. |
