Alternative Reality Technology
Introduction
Virtual Reality Art is at the forefront of Digital Arts as it explores at the same time visual aesthetics, the construction of alternative universes and user interactive experiences. To a large extent, VR Art has kept in touch with the original ideas of VR pioneers, who advocated VR as an endeavour to produce artificial tool aiming to recreate our common sense reality.
Timothy Leary a figure of the counter-culture movement compared virtual reality to a psychedelic experience, namely the distortion of reality experienced under psychoactive substances.1.The development of Virtual Reality, whether scientific, industrial or commercial followed a totally different route, which was the pursuit of realism and illusion. However, VR Art provides an ideal context to revive these early ideas and explore them in the context of state-of-the-art technologies. To that extent, the notion of alternative reality still owes an intellectual debt to the “vision(s)” of Tim Leary.
In that sense, there is a tradition in VR Art to construct alternative worlds, e.g. in Char Davies’ OsmoseTM environment, Louis Bec’s artificial creatures or Maurice Benayoun’s Quarxs™, invisible creatures that bend the rules of Physics. In this context, the objective of the Alterne platform is to facilitate the creation of Virtual Worlds whose physical behaviour departs from our common sense experience, enabling new kinds of virtual explorations and the development of “alternative realities”.
One of the challenges is to improve the conceptual continuity between the creative stages and their technical implementation. This should support the creation of alternative realities from first principles, rather than by the ad hoc scripting of pre-defined effects.
We introduce a novel approach to the creation of Virtual Reality Art installations, which supports the design of alternative worlds, in which laws of Physics can be redefined to induce new user experiences. To implement this concept of "Alternative Reality", we have used Artificial Intelligence techniques to support the definition of the virtual environment behaviour, an approach inspired by Qualitative Reasoning systems. Besides the redefinition of physical laws, we have developed mechanisms for eliciting causal relations between events, as causality plays an important part in users' perception of virtual worlds.
Our installation is a CAVE-like (SAS-Cube) system incorporating a state-of-theart computer game engine as visualisation software, which ha sbeen ported to this immersive display. The event-based system underlying the game engine is used to bypass the native Physics engine and replace it with our Alternative Reality software.
Technology overview
The development of the Alternative Reality technology has included three components acting upon a visualisation engine (Unreal Engine Build 225) (figure1):
An Event Interception System (EIS for short).
A Causal Engine.
A Qualitative Physics Engine (QP Engine for short)
Figure 1: Alternative Reality Technology Architecture
The Event Interception System represents an event-based architecture for the integration of Alternative Reality in VR, which supports the integration of symbolic levels of behaviour in the interactive visualisation system. The EIS discretises all interactions, enabling these to be redefined and controlled by symbolic processes. This system is directly embedded with the visualisation engine and communicates with the Causal and QP engine using UDP sockets. The EIS module defines its own events formalisms, called Context Events and QP Events
The Causal Engine supports new techniques to generate alternative causality and induce causal impressions in the user’s experience. This a system that produces real-time event alterations based on principles. This aspect is based on a specific action formalism supporting the dynamic transformation of actions as they occur in the virtual environment.
A Qualitative Physics Engine supports the definition and the simulation of alternative laws of Physics, which has been based on a well-known symbolic simulation technique: Qualitative Physics.
The Event Interception System
Event Formalism
Context Events (CE for short) are semantic representation of action, while QP Event are event structure attached to object that could activate or participate to Qualitative processes. The rationale for the use of such event formalisms is that they capture the semantics of an application scenario. For instance, they facilitate the formalisation of alternative rules for causality that operate on properties or parameters of the context events.
Figure 5 Context Event and QP event Formalism
Event Recognition Example:
Our formalism is a Cause-Effect representation , where the “cause” part is a formula containing elementary physical events (such as collisions) plus semantic properties of the objects involved, and the “effect” part the transformation undergone by these objects. Figure below shows the CE representation for a breaking action Break-On-Impact(?obj, ?surface). Its “trigger” part corresponds to the event initiating the action (Hit(?obj, ?surface)) and its “effect” part to its effect (that fact that the object exploding). The “condition” field corresponds to physical properties that have to be met by its objects for the CE to be instantiated
Figure 2: Example of Event Recognition and Activation by the EIS
The Causal Engine
System Overview
The Causal Engine modifies “normal” consequences of event occurring into a virtual world. An Event Interception System prevents actions to occur while transmitting their normal consequence to it. Then the Causal Engine generates a set of possible alternative consequences and selects the most plausible ones. The alternative consequences are then re-activated in the world instead of the expected ones
Figure: System Overview (Causal Engine)
Alternative Causality Examples
Our objective is to induce causal perception from collision events in a virtual world.
We hypothesise that causal perception can be elicited through the real-time manipulation of events as they take place. The causal engine creates new co-occurrences that can be interpreted in causal terms by a user. Figure below illustrates this process: the fall of a glass over a table immediately follows by the table shattering instead of the glass breaking upon the impact.
Figure 3 : Artificial Co-occurence generated by the Causal Engine
The Qualitative Physics Engine
System Overview
The system architecture is based on UDP communication between the Qualitative Simulation engine and the Unreal® 2003 engine The EIS intercepts Unreal native events, interprets them at a semantic level (Context Event), and communicates them to the QP engine.
The Qualitative Simulation Engine determines consequences to those intercepted events (QP Events) in order to define a system for alternative reality. We have implemented a system that allows the programmer or artist to develop physical laws using a high-level description. We have implemented a system that uses Qualitative Process Theory for the high-level descriptions.
Figure 39: Example of Process
In QPT the physical laws are represented by processes and it is these processes the programmer or artist needs to develop. An example of a process is given below in figure. These processes in this system are derived from a generic process class. The System tests the individuals for the process and creates a process instance for process, which have the relevant individuals.
The objects are implemented in a similar way in that they derive from a base object and are composed of quantities as are processes.
Figure 38: System Overview (Qualitative Engine)
Alternative Physics Process Example
An example of the alternative effects we can generate is to produce the Heat Aligend property for different processes.Thus Instead of boiling one pan a different pan may boil instead of the pan on the stove. As shown Below (figure 3):
Figure 3 : Example of Alternative law of Physics
