Event-based causality in virtual reality

In this paper, we describe such an environment, in which the user can be presented in real-time with an alternative range of consequences for a given interaction with virtual world objects, thus inducing various perceptions of causality. From a systemic perspective, we can adopt a pragmatic approach, inspired from Humian philosophy, which considers that causal relations are established by the user in response to certain event co-occurrences. To control causal perception in VR, the system comprises the following components: a visualisation engine, an Event Recognition System (together with its specific event formalism that supports event modification), and a causal engine as an Event Modification System, which selects co-occurring events on a rule-based manner. A search process, evaluates alternative consequences using semantic and spatio-contiguity information, such as comparison between candidate objects on which the action consequences should be applied. A first prototype has been fully implemented and is described together with an example real-time simulation.