Our understanding of Virtual Reality (VR) as a communications medium is not as well developed as the technologies of VR themselves. This chapter presents the practical application of a content model of VR, which aims to alleviate this problem. First of all a characterization of the aesthetics of VR is put forward against which the practicalities of the content model can be judged. Then, the content model, based around Perceptual Opportunities (POs), is briefly outlined before it is illustrated in greater detail through its application to the analysis of five Virtual Environments (VEs), two drawn from traditional VR and three from computer games. From the separate analyzes a comparative content analysis is presented which makes surprising links between apparently diverse VEs and allows some insights into VR itself to be drawn.The conclusions document current and future research into POs in particular and VR theory and its practical applications in general.


4.4 Content Analysis Using POs

In this section we will apply POs to the analysis of a range of VEs from both the traditional VR community and the games industry. The documentation of these analyses can be quite lengthy and for this reason only summaries are presented.


4.4.2 Osmose

Osmose is a highly sensual as well as highly abstract VE which uses an HMD with full 3D sound and was designed by the artist Char Davies (2000). It investigates the notion of both bodily presence in a VE as well as mental presence. The former is accomplished through the innovative navigational interface, which allows users to rise or fall as they breathe in or out and to move in the direction they lean towards. The sensuality comes both from the bodily involvement and the translucent organic imagery of the central areas as well as from Davies' aesthetics of ambiguity. There are a number of concurrent worlds within Osmose which blend into each other as the user navigates around. Unlike Hubble (Hubble Space Telescope VTE) there are no further interactions, in the traditional sense, of buttons to press or doors to open etc. Sureties Surprises




In a sense the whole VE is a retainer due to the peripatetic navigation controls which focus the mind/body on floating and exploration. There are specific retainers in the sense of the tree with the firefly sap flowing through it. Retainers may be beautiful rewards as well as doors to open.... A Partial Perceptual Map for Osmose

Moving lights Flow of lights leading to the tree, pond etc.
Following light flows to concentrations of lights in the tree and pond etc.
Partially revealed objects through transparency

Gradual unfolding of Images in next world, moving towards and into

Another world (level)

Spatialized sound
Increasing detail

Delicate transparency, ambiguity of images
Something visual (static)

Peripatetic controls, breathing, leaning Observations

As with Hubble, there are no action analogues, you do not click and drag a mouse instead of walk, and because it is a fantastic world you do not expect to navigate in the same way as in reality. Osmose is highly immersive: you are enveloped by the technology visually (HMD), aurally (spatial sound) and bodily (breath and posture). The world is also highly inducive of presence, partly because of the sensual and illusory nature of the stimuli but also, and very importantly, because of the direct connection between body and navigation in a very fundamental way. The very act of breathing and body posture facilitates movement and must contribute immensely to high levels of presence. This is not the bodiless exploration of Cyberspace (Gibson, 1995) because here the body is made concrete in the VE even though it cannot be seen by the user. Once again, the importance of purpose and genre in determining the nature of the perceptual content is clear. Much of the successful content here would be quite inappropriate in other VE genres. The transparent tree with firefly sap and ambiguous scale would effectively be a PO shock in most other VEs of whatever genre. Research shows that enveloping technology heightens the intensity of the experience (Slater, 1999).

From the PO point of view we can observe that the subtle nature of retainers means that attractor/connector relationships are very important in Osmose. This means that setting goals and planning and undertaking their attainment are of primary importance. The high-level goals are realized by each user in their own way. Osmose employs attractor/connector relationships rather than specific retainers and thus emphasizes intention over perceivable consequence. We will see this later in some of the games analyzed.


4.5 Comparative Content Analysis

Interestingly, the three games studied are desktop, PC-based and nonimmersive, while the other two VEs are highly immersive HMD-based. We are analysing the content and not technology of VEs. Using POs as the basis to undertake comparative content analysis is a fairly recent enterprise, but we are in a position to start to make the kinds of constructive comparisons between diverse VEs that Doug Church calls for (Church, 1999).

For instance, we can see that all the VEs studied, with the exception perhaps of the Hubble VTE, make extensive use of peripatetic retainers, i.e. additional controls that follow the user around. Interaction is not just about specific affordances such as opening doors or pulling levers. Peripatetic retainers are directly related to a user's ability to feel part of the world – they are the user's specific interaction in the VE and are thus conducive to agency and presence in particular.

Perceptual realism, the internal consistency of worlds, appears more important than adherence to the real world. We see this particularly in Osmose, which does not model aspects of everyday life, social realism (Lombard and Ditton, 1997), in any real sense. However, all the VEs studied have a range of sureties that seek to convince the user of the internal consistency of that particular VE. Yet their approaches in this respect differ markedly even though three of them, Hubble, Sincity and Driver, all purport to model aspects at least of the real world. There is no co-presence in the high-end VEs, whereas co-presence is important to all the game VEs. Being present with others is a major presence factor and particularly useful in desktop VEs where the immersive capacity of the technology is low. In the three games sureties for presence have been carefully thought through, yet again they differ markedly, from appropriate car horns to highly alert prison guards.

Hubble, Sincity, Driver and Osmose all make use of alien attractors without apparently detracting from presence. In Hubble there is the red pointer on the space suit glove which can be used for accurate selection of components as well as objects which can be indicated with green dots by the help system. In Driver we have the red dots, arrows and exclamation marks all indicating variations on the end of a level. In Sincity we have floating guns and boxes of health. In Osmose we have partially obscured objects from adjacent worlds which can seem incongruous as well as mysterious. Alien attractors in Hubble and Driver are used as help in an informative way, whereas those in Sincity are direct help in the sense that they represent resource users need to complete levels. In Osmose the appearance of partially obscured text, for instance, at the edge of an organic world could be construed as an alien attractor very similar to the punctuation marks in Driver and acts similarly as a wayfinder.

All the VEs provide strongly identified attractors which offer users plenty of opportunity for goal setting and planning. In Osmose the flows of lights act as attractors in the first instance then act as connectors to guide visitors along to major areas of spectacle and finally as retainers to bathe in. In Sincity the principal attractors are ricocheting bullets and minute patterns of a few pixels moving, usually at a distance, to indicate the location of your opponent(s). In Hubble there is a predetermined pattern of activity to follow in order to complete each maintenance task. In Thief exploration and short-term planning are mandated and there are attractors usual to the genre, such as doors, branching corridors and valuable objects. There are also things such as keys which would be collected by someone who knew the genre but would not be quite so collectable to someone new to it.

Driver and Thief are very similar games despite the fact that their genres are different - one is a driving game while the other is a sneak-'em-up. Both use fake endings to prolong levels. Both use analogues as connectors - health indicators, shadow, possession and shadow indicators, etc. are all 2D, as are the damage indicator, time indicator and local map in Driver. There is not a great deal of skill involved in fighting or shooting arrows, unlike Driver where you have to have reasonable driving skills in order to complete levels and avoid manic police cars. Both rely on attractor/connector patterns to build suspense and, like Osmose, do not have clearly identified retainers.

Sincity and Hubble both use clearly identified retainers with associated attractors as a means of delivering the purpose of the world. In terms of Sincity, shoot'em-ups rely completely on the intense bouts of fighting to deliver purpose. The patterns of connectors can be used for planning and preparation, but drama comes from shootouts. In games such as these, unless you get to the retainers on a regular basis the game soon becomes pointless. All the connectors you plan with don't deliver purpose but simply allow you to accumulate weapons and ammo, and set yourself up in a good ambush point. The same is probably true, though in a different way, of VTEs where the objective is conscious learning through executing relevant tasks. One could argue that there are retainers in both Osmose and Driver, but they are far more integrated with the patterns of attractors and retainers in the VE, and can very often be ignored or missed altogether, still allowing users to achieve their purpose.

Osmose and Sincity have the most open perceptual maps in the sense that there is no right or wrong, complete or incomplete, pre-ordering of user activity. In the former case this is because all levels are equally open to visitors and the purpose is for the user to find and/or construct their own interpretation of the meaning of the VE. In the latter case the open structure of the perceptual map is due to the nature of DM levels that require flow concentrated in a relatively limited area to enhance the drama and sense of action. One of the attractions of DM levels is that the patterns of activity are based almost entirely on the behaviour of other humans. In Hubble there is a single route through the perceptual map in order to effect the repairs appropriately. Hubble is also structured in distinct levels, much in the way Driver and most other computer games are.

As Driver and Thief are single-player games we find that their perceptual maps are more structured than Osmose and Sincity but less structured than Hubble. There are often a variety of routes to follow and tasks can often be undertaken in a variety of ways and in various orders. This is due to the nature of SP levels where agency constrained and enhanced by challenges ahead replaces the excitement of the human interaction, albeit at a distance, of Sincity.

In terms of narrative potential we can make some interesting observations:

The outcome of the analyses allows us to suggest that POs are indeed a practical content model for VEs and allow us to compare and contrast VEs from a diverse range of application areas. Comparative content analysis allows us to:

4.6 Conclusions

As a practically oriented model POs are being validated and put to use in a number of ways. From the outset POs were intended as a practical model of VR content to support VE development. One of the roles of a model is to test it against data generated in appropriate manners in order to see how the model correlates with actual experience. The work presented in this chapter is part of that process.

Perceptual opportunities arose first out of the direct practice of VE creation and later from VEs viewed as the object of investigation. In a very real sense the mode of investigation was the series of trials and errors the author encountered in learning to build VEs and trying to make sense of why some apparently obvious content inclusions appeared to go largely unnoticed while others perhaps less obvious caught visitors' attentions readily. The process of trial and error was made positive through a series of observations of and discussions with some 200 users of the VRML model of the cliff lift discussed in some detail above (Fencott, 1999b). POs arose out of a desire to generalize the mistakes and successes of the cliff lift's development process. For several years now the model has been used to teach students, undergraduates and graduates the principles of VE design. In discussion with students it has become clear that the perceptual map of the cliff lift does indeed achieve its purpose, but also that the goals and plans users construct are not as straightforward as the map would like to suggest. For instance, many students do indeed say that they established goals as predicted by the perceptual map but that they put off achieving those goals until they had explored more and found out if there was anything else to do. Through such exploration they would establish a number of goals, prioritize them and then set about planning and achieving them. The results are the desired ones, but the process is more complex than simple perceptual maps would suggest.

A different but complementary form of validation is to conduct experiments to ascertain whether the general and particular predictions of a perceptual map for a given VE induce the expected behaviours from users. For each of the various forms of PO there are measures which can be experimentally investigated. This work is at an early stage, but pilot experiments have been run. One early finding is that the power of attractors is easily offset by the effort required to realize goals associated with them. This work is currently proceeding, and an experimental investigation to correlate actual user data from interacting with the cliff lift VE, making use of eye-tracking technology, with the predictions of the perceptual map for the cliff lift is about to be run.

POs are not a universal panacea for the problems of VE design, but focus particularly on designing VEs to communicate effectively. POs, along with a variety of other techniques, many of them discussed in Section 4.2, can be correlated to form a design methodology for VEs (Fencott, 1999c).

If VR is ever to be more than motor skills training or a generator of visceral thrills we will need to master the more subtle communicative qualities it surely possesses. How can we, for instance, create atmosphere, suspense and drama, trigger appropriate emotional responses, convey concepts and abstract ideas, and facilitate the experiential creation of narrative? It is the purpose of this chapter to demonstrate that POs are a basis from which we can go on to achieve such mastery. Work is now afoot to use POs to undertake a more detailed analysis of the tropes of VR so that we may come to understand more rigorously the communicative potential of the medium.



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Last verified: August 1st 2013.