Résumé : This paper presents an efficient way to provide a graphical interactive visualisation to a noninteractive existing object oriented application. Assuming that the initial application uses an ‘Abstract Factory' pattern (GoF87) in order to create new objects, our aim is achieved by using the PAC-Amodeus model and extending the existing objects to create intermediate components, using object oriented techniques: inheritance, polymorphism and dynamic binding, using the ‘Proxy' pattern (GoF207). Although our field of interest is physical and behavioural simulation, the techniques developed in this paper can be applied to any non–interactive object oriented existing kernel. Then, we present a complete simulation example ‘Bugs life' to illustrate the use of our method. Finally, we point out the limits of our approach, and we suggest new directions for further work.