NA SENDA DA IMAGEM A Representação ea Tecnologia na Arte

II. 3D authoring tools
Authoring is the tradition of collecting,
structuring and presenting information in the
form of a “document” rendered in some medium
or media. Until recently, the document has been
static, in the sense that once rendered, it is fixed
for all time and for all readers. Promising new
technologies have recently come into existence
that could alleviate some of the limitations of
this difficult undertaking.
In the traditional approach to the model of
authoring, the task of an author is to collect a
coherent body of information, structure it in a
meaningful and interesting way, and present it
in an appropriate fashion to a set of readers or
viewers of the eventual work. A user-tailored
presentation is still not possible.
This approach changes when the author
supplies a communicative goal to the document.
Making explicit this intention at the time the
document is specified opens the door to truly
user-specific document presentation.
Information and presentation spaces can be
clearly separated. The incentive to provide
presentations, which have been particularized to
the needs and interests of the viewers, are very
strong concerning multimedia data. Traditional
authoring paradigms do not support such runtime
determination of form and content.
Interactive multimedia systems can be
roughly categorized by what kind of authoring
and presentation metaphors they employ. There
are three main ways of authoring presentations
on a computer.
An ultra high-level visual authoring
environment. Icon-based visual (nonscripted)
systems have the distinct
advantage that the author need not type a
single line of code to create a
presentation. The problem with visual
authoring systems is that they stifle the
creativity of the artist by forcing him/her
to work with a set of “mainstream”
primitives that the system engineers have
somehow determined to be most useful.
A high-level scripting language. At the
other end of the spectrum, it is possible
to author a presentation by writing a
specialised computer program in a lowlevel
language such as C or C++. The
advantage of this approach is that
expressivity, extensibility, and efficiency
are at a ma ximum. Unfortunately, unless
the artist is also a computer scientist, the
process of learning is likely to frustrate
the amateur to an extreme.
A low-level computer program. Many
systems that lie in between these two
authoring extremes employ some kind of
“scripting language”', but may provide
more intuitive syntax and higher-level
constructs useful in multimedia
situations.
Four general paradigms exist for multimedia
authoring systems.
Graph-based authoring, using a
schematic diagram of the control flow
interactions among multimedia objects.
Timeline-based authoring, where data
flow of the presentation is described
relative to a common time axis.
Program-based authoring:, describing the
positions and timings of individual
objects using a text -based specification.
Structure-based authoring, grouping
objects based on presentation content.
Perhaps, the most important problem is that
the vast majority of recent systems handle
interactivity and personalization in an
unbelievably crude and inelegant manner.
III. RELATED WORK
Multimedia authoring can be used to create
anything from simple slide shows to full-blown
games and interactive applications. Multimedia
authoring tools are used to create interactive
presentations, screen savers, games, CDs and
DVDs.
DINAH is an authoring tool used for the
creation of interactive narrative (Ventura and
Brogan, 2002). The author fills a relational
database with many small story clips, each one
tagged with constraints that specify how it can
be combined with others. After the clips are
labelled, they are read into a database and
assembled by the narrative engine at run time.
At certain points in the story, DINAH
dynamically selects the most appropriate story
clips and prompts the user to play the role of the
avatar, thus building the story. The algorithms
that combine the clips form a narrative engine,
which coordinates the concatenation of clips
into a story.
MPEG-4 authoring is quite a challenge. Far
from the “simplicity” of MPEG-2, it allows the
content creator to compose together spatially
and temporally large numbers of objects of
many different types: video, still image, speech
synthesis, voice, music, text, 2D graphics, 3D
and more. MPEG-Pro is a software dedicated to
authoring 2D multimedia compliant with the
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Copyright © ARTECH 2004 – 1º Workshop Luso-Galaico de Artes Digitais 12 de Julho de 2004, FC - UL