In general, the Principle of Predicative Naturalism is realized as a constraint system propagating restrictions through the hierarchy of representational elements and their visual components until a stable association has been established. The following parameters act as additional constraints:
(a) the order of degree of naturalism between the style values (e.g., the degree of naturalism decreases from ‘natural color’ to ‘uncolored’ to ‘unnatural colors’), (b) the dependencies between the different visual components considered by the style
description (color, texture, form, place, configuration), and
(c) the impact a particular attribution of a rhetoric function to a visual component has on the other components of that representational element.
88
Figure 110 presents three gray-scale examples: color and texture parameters are ig- nored here for simplicity.89
Let us assume that the communicative intention given asso- ciates the background (a table top) as nominatoric, and a bunny’s shape and the con- figuration of its (body-) parts as predicative, while the relative position of the bunny with respect to the background objects is also marked as known already to the beholders in question. Then, it is sufficient for the background to be drawn in outline and without parts (“atomic”). For the bunny however, form and configuration parameters should be maximal (i.e., value “natural”). If only the bunny’s configuration is predicative, the form parameter changes to “outline”: the four components are clearly discernable.
The third example is more complicated since the place of an element can only be predicative if the configuration of the complete scene is emphasized, as well. Therefore, using the bunny’s place as predicative property has to be propagated up in the hierarchy of representation elements to the configuration of the scene, and from there down again to the place parameter of the other children, i.e., all the background elements. The inner contours of the tabletop are selected while the configuration of the bunny becomes atomic and only outlines need to be shown. The graphic clearly emphasizes the bunny being almost at the border (in consequence, its danger to fall off is here more evident). 5.3 A Border Line Case: Immersion
Images in highly immersive systems are the interactive pendant of trompe l’œil pictures. Using them may be seen as a borderline case of image use due to the dominance of the deceptive reception mode. As was already described for the immersant in the art work Osmose in section 4.4.5.3, the sign character of the presentation disappears at all: the perceptoid context builder becomes a genuin situational context. With respect to aesthetic considerations, GRAU explains in his essay on Osmose [2003]:
In virtual environments, a fragile, core element of art comes under threat: the observer's act of distancing that is a prerequisite for any critical reflection. Aesthetic distance always comprises the possibility of attaining an overall view, of understanding organization, structure, and function, and achieving a critical appraisal.
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The system described in [HALPER ET AL. 2002] was used to construct parts of Figure 109. Due to its
modular organisation of simple style-varying operations, it is an ideal candidate for interpreting the style descriptions finally associated with the hierarchy of representation elements of the picture.
Background: all nominatoric Bunny: place nominatoric shape predicative config. predicative Background: « . , . , outline,
atomic»
Bunny: « . , . , natural, natural»
Background: all nominatoric Bunny: place nominatoric shape nominatoric config. predicative
Background: « . , . , outline, atomic»
Bunny: « . , . , inner contours, natural»
Backgr.: initially all nominatoric Bunny: shape nominatoric config. nominatoric place predicative (⇒ Backgr.: config. → predica-
tive) Background: « . , . , inner con-
tours, reduced»
Bunny: « . , . , outline, atomic»
The act of distancing is indeed not restricted to aesthetic considerations in the close sense but forms the core aspect of the symbolic mode: evoking contexts that are not the situational context at hand is the major function of signs. ‘Evoking a context’ means not only immediately activating certain spontaneous reactions, but also the ability of post- poning those reactions to the context evoked though not present (cf. Sect. 3.5.1). Thus, one of the components defining the concept »picture« is missing. If the use of pictures in highly immersive systems aims at a reception in the pure deceptive mode by sup- pressing any factors able to activate the viewer’s symbolic mode, then there are indeed no pictures used at all, at least for the “immersants” who do not spontaneously reflect about their situation.
Nevertheless, an important part of computational visualistics deals exactly with this borderline case of image use. As has been mentioned already in chapter 3, the producers of trompe l’œil pictures as well as of immersive systems cannot share the reduced recep- tion mode: they in fact deal with pictures as perceptoid signs that are intended to be mis- taken – at least for a time or to a certain degree. Usually, we do not meet immersants that do not at all reflect their specific situation: highly immersive systems still need so much technical effort and preparation that nobody simply find themselves in such a sys- tem without noticing it. Correspondingly, they are not in a pure deceptive mode but in the immersive mode where the postponing of spontaneous reactions is strongly reduced, not totally absent. Recall the situation in cinema when we appear to be confronted with a life-like Tyrannosaurus rex threatening to attack us: we know that it is an illusion (a sign we show to ourselves), consequently having a lot of spontaneous reactions that are generally postponed; but we allow those reactions to surface to some degree, which is one of the pleasures of viewing such films.
Long before expressions like ‘virtual reality’ or ‘immersive systems’ have become popular, S. LEM investigated different levels of immersion under the name of ‘phan-
tomatics’ [LEM 1964]. Present attempts are based essentially on technical devices pro-
jecting pictures on more or less flat smooth surfaces covering all of the field of view: they can be viewed in the ordinary sense.90
Sound is being emitted by speakers in more or less sophisticated manners, also to be heard in the traditional way. Quite obviously, only distance senses can be easily deceived by that form of immersive systems. Many contact senses are much harder to be deceived – recall all the sensations from our skins. The feedback from the immersant’s actions is also mostly restricted to very specific and very small channels: a mouse, a data glove, or a data suit at most.
As an improvement of immersion, LEM imagines what he calls ‘peripheral phan-
tomatics’, where technical devices directly manipulate the immersant’s peripheral nerv- ous system, feeding the sensoric nerves and taking signals from the effectoric nerves: the pictures or sounds used can then be inspected only by additional devices. Still, the immersant’s body with its movements and the monitoring proprioceptors form a source of “disturbance” to the immersion. Therefore, another step is introduced: LEM’s expres-
sion ‘central phantomatics’ refers to the hypothetical technology that allows technical devices to directly manipulate the immersant’s central nervous system, overwriting any bodily signals including those from the sense organs, and intercepting any nerve pulses controlling (real) motion. That is: for the immersant, the physical body is completely replaced by the avatar. He or she seemingly exists only in “cyberspace”.
90
Current experimental devices projecting light directly into the eye form the only exception known to the author so far.
Beside the aspect of plausibility, LEM is basically interested in the epistemological
question whether (and how) an immersant of any of those levels would be able to detect the deception – indeed a modern pendant on DESCARTES’ reflection on the nature of
truth under the assumption of a deceiving deity.91
This is not the place to investigate those problems.
Of course: the expression ‘immersion’ is not only a question of technology – more likely a question of purpose and concentration. Humans are very well able to be com- pletely absorbed in reading a novel ignoring most of their situational context (even up to the bodily needs to some degree) evoking mental imaginations of what they read. High degrees of technically induced deceptive mode are relevant in simulations, e.g. for pilot training. In other applications, the equilibrium between the symbolic and deceptive components of reception is more complicated. Different purposes lead essentially to dif- ferent possibilities of interactions. Two particular cases – virtual architecture and virtual institutes – are presented in the following together with a description of the particular conditions and intentions of application, demonstrating alternative needs for deceptive or immersive reception modes of the pictures used.