Visualisation and simulation with object-oriented networks

Among the existing systems, visual programming environments address best these issues. However, producing interactive simulations and visualisations is still a difficult task. This defines the main research objective of this thesis: The development and implementation of concepts and techniques to combine visualisation, simulation, and application construction in an interactive, easy to use, generic environment. The aim is to produce an environment in which the above mentioned activities can be learnt and carried out easily by a researcher. Working with such an environment should decrease the amount of time usually spent in redesigning existing software elements such as graphics interfaces, existing computational modules, and general infrastructure code. Writing new computational components or importing existing ones should be simple and automatic enough to make using the envisaged system an attractive option for a non programmer expert. Besides this, all proven successful elements of an interactive simulation and visualisation environment should be provided, such as visual programming, graphics user interfaces, direct manipulation, and so on. Finally, a large palette of existing scientific computation, data processing, and visualisation components should be integrated in the proposed system. On one hand, this should prove our claims of openness and easy code integration. On the other hand, this should provide the concrete set of tools needed for building a range of scientific applications and visualisations. This thesis is structured as follows. Chapter 2 defines the context of our work. The scientific research environment is presented and partitioned into the three roles of end user, application designer, and component developer. The interactions between these roles and their specific requirements are described and lead to a more precise formulation of our problem statement. Chapter 3 presents the most used architectures for simulation and visualisation systems: the monolithic system, the application library, and the framework. The advantages and disadvantages of these architectural models are then discussed in relation with our problem statement requirements. The main conclusion drawn is that no single existing architectural model suffices, and that what is needed is a combination of the features present in all three models. Chapter 4 introduces the new architectural model we propose, based on the combination of object-orientation in form of the C++ language and dataflow modelling in the new MC++ language. Chapter 5 presents VISSION, an interactive simulation and visualisation environment constructed on the introduced new architectural model, and shows how the usual tasks of application construction, steering, and visualisation are addressed. In chapter 6, the implementation of VISSIONis architectural model is described in terms of its component parts. Chapter 7 presents the applications of VISSION to numerical simulation, while chapter 8 focuses on its visualisation and graphics applications. Finally, chapter 9 concludes the thesis and outlines possible direction for future research