Theatricality
and Levels of Believability in Graphical Virtual Environments.
David K. Manley
Liverpool John Moores
University,
Liverpool, Merseyside.
Published in: Paton and
Neilson. Visual Representations and Interpretations, Springer-Verlag, London.
1999
Abstract
The experience theatre has in the creation of
believable performance environments, could be constructively transferred to the
emerging field of computer virtual environments...There seems to me to be
little to differentiate between these worlds...other than the medium of
delivery.
1 Introduction
My background of twenty years as a professional theatre technician had given me the opportunity to work in and with many varied performance spaces. All of them 3D, all of them to a greater or lesser degree interactive, and all of them designed using the common collected experience of theatre. A common experience backed up by arguably over a thousands years of development. The similarity between all those performance spaces was that they sought to be, for the watching audience, a believable environment.
I first became aware of a critical link between theatre and computer science when I was given the book, "Computers as Theatre" [1]. Its proposal that theatre could define an underlying philosophy for computer human action was fascinating. But it was the title that had really gripped my imagination. The idea that computer worlds could be linked to theatre worlds made sense of my past subjective experience and my knowledge of the developing world of computer supported virtual environments.
Believability,
as a primary design consideration, should not be confused with realistic or
naturalistic. The arguments about realism and naturalism have been going on
since the 1870’s and is evidenced in the work of writers such as August
Strindberg and Gerhart Hauptmann [2]. In this area, realism can be thought to
destructuralise complex realistic globals into smaller usable entities and then
re use those entities overlaid onto other carriers. I.e. an unrealistic cartoon
character can show realistic anger. Naturalism in this work is considered as
more environmental. A cartoon character is ‘natural’ to a cartoon world as a
human is natural to our human world but we would be unnatural in a cartoon
world and vice versa. Believability
simply means the ability to accept as true.
Theatrical rules governing this believability have been used for
thousands of year’s [3] within theatre and I believe on the whole to good
effect.
Theatricality
and its consideration of three-dimensional space make it a candidate for
comparison with architectural techniques when addressing the design of virtual
environments. Where they differ is in that theatricality also seeks to design
the representation of the content of that space. An architect will not seek to
tell a user of a building what clothes to wear but a theatre designer will!
This designed integration of space and content representation may give it an
edge over architectural methods in fields such as the representation of data in
virtual CSCW [4] environments, both immersive and desktop.
But
most importantly, it is in the use of theatres experience in the creation of
believable environments that I see most opportunity. There seems to me to be
little to differentiate between the worlds of theatrical performance
environments and the developing field of computer virtual environments, other
than the medium of delivery. Both work in bounded environments using three
dimensional spatial awareness, both use light to illuminate, to colour and to
give orientation, both use spatial auditory awareness and both use human
psychology.
I
am not saying that the rules of theatrical design are unique; only that
theatricality has brought together and integrated concepts and ideas from many
fields. Consider it a unification point for virtual environment design. It is this ability to absorb and integrate
ideas from other sometimes-contrary areas that has given it such strength. It may prove fruitful to revisit these other
areas and construct a new unifying theory, (unifying both container design and
contained object design) if theatricality proves weaker than I anticipate.
Until then it would be a case of trying to reinvent the wheel.
3 Elements of
theatricality for design consideration.
The
following are some of the main considerations for inclusion in the design stage
of a virtual environment from a theatrical point of view. These are often not
included or are viewed from a different approach. These are in addition to
normal considerations such as file size, intention, content etc.
There
seem to be two ways to structure these design elements. One is to use a
departmental approach where standard theatre departments such as LX dept for
lighting, SFX for sound, wardrobe, set design etc. are used with their
associated individual design methodologies, but I think this is taking the
metaphor too far. Instead I have chosen a series of titled fields. This seems
to me to be a more flexible approach to something that is still very much under
development.
From
now on my use of the word audience is intended to cover, single or multiple
agents, both human and computer; intelligent or otherwise.
3.1 Convention
A
dramatic convention is something that can be used as a substitute for reality,
but is experienced by an audience not as a symbol, but as the reality
itself. For example, on stage a tree
may be represented by a mere branch, the rest of the tree being inferred. This could be a useful tool in the design of
virtual environments, were considerations of the bandwidth usage of an object
are important. It is something, I think most computer users are culturally
aware of and subconsciously use, to the extent that they often don't realise
the huge leaps of credibility they are making.
I have a hypothesis that this could be a part of inherited memory,
natural to all cultures in so far as they are or have been through an
influentially shamanic stage. Sir James Frazer states, the Shamanic second law
of magic; “The Law of Similarity” as
“The magician infers that he can produce any effect he
desires merely by imitating it.”
This
also links into ideas of why symbolism and semiotics can be so powerful in,
what is after all, an environment devoted to the manipulation of symbols.
3.2 Focus
It
is possible to direct the focus of attention to specific parts of a world using
the same tricks as a stage designer. To use light, not just as a prerequisite
of vision, but on another more subtle level. If an audience looks onto a new
scene in a performance, their view tends to be drawn to the lighter areas and
afterwards to darker areas. This could be used as a ‘guide’ mechanism to order
the viewing of a virtual world. Small scintillation’s of light will draw
attention to an object and thus equally draw attention away from other objects.
There
are other methods of focus such as colour response, additive and subtractive
colour mixing, and dynamic light changes. These could be useful methods in a
CSCW environment to create an awareness of other users by the depth of focus
those users have in relation to individual view fields. They could also form
the basis of a filter mechanism for changing dynamically the level and quantity
of data representation viewed by an individual within a PIT environment [16].
3.3 Set Design
A
Set design delineates a performance space necessary for the completion of a
theatrical process and can both inform and frame the action. In the same way
areas of a virtual environment could be delineated to allow for the completion
of a virtual event. To render all the parts of a virtual world up to a true
horizon could be a massive computational task and pointless if only a small
section was required. So some form of boundary delineation is usually sensible
if not actually vital. I think in many
virtual worlds, this boundary delineation, though practical, only makes pretty
and does not inform. This is not necessarily wrong, but seems a wasted
opportunity. For example in a performance environment, a world beyond and
integral with the viewed area is normally suggested. The degree to which an
audience can visually and mentally associate with this world is carefully
controlled via the textural, visual, and theatrical elements that are placed in
front of them. In other words the stage set. Within a virtual environment
degrees of fogging can limit view distance and thus the amount of the total
environment on view. The density of the fog could delineate a boundary area (of
variable depth). Inside which an awareness of, but no clear vision of the
objects it contained would be allowed. The depth of this area could either be
fixed or dynamic. The object content of this area, as opposed to object
clarity, could be filtered (as in control of focus) by the use of additive and
subtractive colour mixing. Thus the boundary layer could both frame and inform.
3.4 Believability
As
I discussed earlier, believability, is a missing element in many virtual worlds
and should be considered as a design field. If a virtual environment can be
made to be believable then it arguably doesn’t need to be realistic and this
has implications for the amount of bandwidth used. Less bandwidth would be
needed if an object could be represented believably with 80 polygons where
previously it was represented using 200 polygons. I also think that a
believable world could extrapolate to a world that is comfortable for people to
work in. This comfort would lead to ease in assimilation of the working methods
of that world. It could be a factor in helping make real world skill sets
transferable to virtual worlds and reduce learning curves. Though logical this
is however still at present speculation, and needs developing, testing and
validating.
3.5 Kinaesthetics
This is the appreciation of movement within space. It is a main consideration of dance and is of vital importance at the blocking stage of theatrical rehearsals. Kinaesthetics can effect focus and can make movements believable by overlaying a chosen aesthetic. The eye picks up on movement within a still field, and this can be used for direct representation of entity values and for present’s awareness. A PIT environment object needing to occupy a distant co-ordinate to satisfy its representational function could also be give an oscillatory movement to increase its visibility in comparison to closer objects. Various speeds and axis of spin could be used as representations of other relevant data fields as could the size of orbit. Kinaesthetics could be used to represent not only a change from state A, to state B, but believably reflect the process of the change itself.
3.6 Emotion Transfer
There
have been experiments done with trained actors to see what it is that causes
transfer of emotion. Experiments such as those carried out by Ekman and
Birdwhistell. [17] They looked into how, a type of gesture called illustrators
could be used to reveal information about the speaker's attitudes and emotions. None of these to my mind have been
conclusive but they do strongly suggest that the perception of emotion does not
need to always be derived from an emotional event. Western actors are often
taught to look into their emotional past to create, for example, an expression
of sadness. This derives from the
teaching of Stanislavski. [18] This is ingrained to the extent that often
acting that does not contain felt emotion is derided as ‘poor’. Yet performance without the aid of emotion
is the basis of Kathakali theatre in India [19]. A performer in this form would
be derided if he ‘lost control’ and allowed emotion into his performance. Yet
both seek to control the emotional empathy of an audience. The point of this is
that an audience can perceive emotion from a non-emotional event. It should therefore be possible to create a
sense of emotion within a virtual environment, without resorting to more
bandwidth heavy methods such as video links, facial and postural simulators and
all their associated hardware. The fixed expressional face code and postural
code of Kathakali theatre applied to avatar representations of collaborative
workers in virtual environments could form a model for future work.
3.7 Patterns of sensory phenomena
At this point of development
conclusions may be misleading as they could lead to a false sense of
completion; rather I would like to sum up with two comments.
This work describes a
possible starting point for the consideration of the design of computer supported virtual environments. It
has enough validity to make it worthwhile to develop further and to look at its
foundation in greater detail.
Its
aim is to formulate an approach that
·
is repeatable.
·
has a design consistency
to allow familiarity of usage in many different types of worlds and on
different platforms.
·
guides but does not
inhibit creativity and originality.
·
gives a system for
comparative benchmarks for considering other worlds.
References
1.
Laurel B. Computers as
theatre, Addison-Wesley, Massachusetts, 1996
2.
Jacabus L A. The Bedford
introduction to drama, Bedford, New York, 1989
3.
Aristotle. Poetics,
Penguin, London, 1996
4.
CSCW. Computer supported
collaborative workspace
5.
CALVIN. Collaborative
Architecture via Immersive Navigation, http://evlweb.
eecs.uic.edu/spiff/calvin/ieeecga/index.html
6.
Ninth edition of the
Concise Oxford Dictionary.
7.
DIVE. Distributed
Interactive Virtual Environment, http://www.sics.se/ dive/dive.html
8.
Blaxxun World.
http://www.blaxxun.com/vrml/home/ccpro2.html
9.
Viscape.
http://www.myweb.de/phantasus/aptsec.htm
10. MUD, Multi User Domain
11. See [6]
12. Worldsaway, http://www.worldsaway.com/home.shtml
13. Dr Harrop P. Head of Dance, Drama and Theatre studies,
University College Chester, UK.
14. Cardeña E and Beard J, Truthful Trickery: Shamanism,
Acting and Reality. Performance Practice, 1996; 3:31-45
15. Dixon S. Digital Performance, Unpublished Talk,
University College Chester, 1998.
16. Populated Information Terrain’s,
http://www.crg.computer-science.nottingham. ac.uk/research/applications/pits/
17. Lynn S, Messing. The Use of Bimodal Communication by
Hearing Female Signers, PhD Thesis, University of Delaware, Newark, 1993, chapter
4
18. Stanislavski C. My Life in Art, Translator Robbins J
Jeyre, Methuen, London, 1980
19. Barba E. A dictionary of theatre anthropology the
secret art of the performer, Routlege, London, 1991