Photorealistic vs. Non-Photorealistic Renderings

in Virtual Environments

Runddy D. Ramilo, MSc, BSc (Arch) PhD (Architecture) candidate, Australia

Abstract

Design is a creative
activity that is complex and influenced by numerous factors. The new
trend in design presentations explore and takes place in a Virtual
Environments wherein computer-simulated environment is used to
communicate and perceive design. Most researches on Virtual
Environments (VE) have been focused on Photorealistic (PR) simulation
environments but there has been inadequate research on the use of VE in
Non-Photorealistic (NPR) presentations to explore the most efficient
method of interior design presentation.

This
article discusses the use of VE to support the necessary means of
interior design presentations i.e. Photorealistic or Non-photorealistic
Renderings. Perception of spatial volumes within VE is assessed through
comparison of representations using Photorealistic and
Non-photorealistic means of presentations. A research was conducted to investigate the relative effectiveness of both Photorealistic and Non-photorealistic in immersive
and non-immersive VE by interpretation and communication through
design. It was found out that Non-photorealistic renderings are still
the most preferred method of renderings by designers and clients.

Keywords: Virtual Environments, Design, Photorealistic, Non-photorealistic Renderings

Virtual reality is a technology which allows a user to interact with a computer-simulated environment. Most current virtual  environments are primarily made for visual experiences that displayed either on a computer screen or stereoscopic displays with simulations which include additional sensory information, such as sound through speakers or headphones.
Immersive Virtual Environments (IVEs) perceptually surrounds the user,
increasing the user’s sense of presence being within it. Virtual
environments have been increasingly used for a variety of contexts such
as learning, business, engineering, architecture and design.

As
the modern world develops and utilizes design technology for
architecture and interior design, the subsequent demand for digital
presentations had popularly emerged. Current visualization research
have focused on achieving Photorealism (PR) in which essentially
concerned with rendering images as ‘realistically’ as possible through
the integration of physics and algorithms (Halper et al, 2003). In
virtual environments walkthroughs and picture-perfect simulations of
objects have defined a practice where Photorealism  is considered as
perhaps the most important measure of a successful representation
(Roussou and Drettakis, 2003). Since its emergence, the field of computer graphics has concentrated on making 3d images that are indistinguishable from reality. Figure 1 and 2 are examples
of Photorealistic interior design presentation from Wilson and
Associates, world’s leading interior design firm.

hi runddy images to follow

On the other hand, while most designers and
researchers in design and computer graphics have focused on creating
Photorealistic presentations some have concentrated on
Non-photorealistic presentations. Some have evaded the use of
technology and most are inspired by human drawing techniques that are
water color, pen and ink, crayons, markers and pencils. With the
traditional techniques and human skills a lot in interior design
practice are still using these means of presentations as it relates to
creative and artistic creations of designs. According to Mausch and
Magdeburg (2002), Non-photorealistic renderings (NPR) are beneficial in
many ways as they can support story telling, expressive, giving the
image a certain artistic look and feel. Masuch and Rober (2001) also
encourage the use of NPR as a good alternative as it is more artistic
and convey a creative sense of design. A number of research article
(Harper et al, 2003), (Kang, 2000) and Klein et al, 2000) states that
Non-photorealistic .renditions appear more natural and are perceived
far more easily than complicated technical drawings. Figure 3 and 4 are
examples of Non-photorealistic in water color and figure 3 and 4
interior design presentation from Wilson and Associates and Designphase
Hospitality respectively.

Design Presentations in Practice

In the beginning of the emergence of digital presentations in interior
design, many have been enthusiasts and have taken advantages on the use
of technology for precise creation of design and presentations. Several
designers have focused in 3d modelling and construction detailing and
others started creating designs in 3d worlds.

Several big architectural
and interior design firms like KPF, Aedas, HOK and many others appears
to intentionally trash out the traditional non-photorealistic means of
presentations and have shifted to 3d modelling resulting to produce a
Photorealistic rendition that range from still life to walkthrough
animations. Ramilo (2007) points out that Photorealistic renderings has
been a good tool for visual communication wherein architects and
designers can portray their imaginations into virtual reality. This
provides the opportunity to extract the best from variety of different
designs for built environment and realizing emotions of interior spaces.

However,
as the field of digital media is becoming mature and virtual itself
starts to develop a ‘picturesque language’ and even more realistic,
there is a realization that in many cases what may interest is not so
much about Photorealistic presentations but an image that communicates
and easily perceive its underlying meaning. World’s leading interior
design companies like Hirsch Bedner and Associates, Wilson and
Associates, and Gensler are still using the traditional
Non-photorealistic presentations and believed that it is about design
as creating creative spaces and convincing environments, regardless if
the imagery realistically emulates the physical properties of the world
or not. Furthermore, as Photorealistic rendition is technically tedious
and costly in which consumed a lot more time and efforts than
Non-photorealistic. In many small and medium size design companies,
Non-photorealistic  presentations appears to be more efficient as it
can be done with several styles and options that is water colors,
markers and others; in a lesser efforts that can be done by most of the
designers. The table 1 below is a simple graphical representation that
shows considerable types of design presentations that is currently used
in interior design practice.

Table 1. Graphical representation of design presentations by the Author

Nowadays,
finding the most quoted efficient interior design presentations has
been a difficult task. What may appear graphically good and meaningful
to other clients might be worst to other people with different
background. In this study, it is argued that design is not just about
form and images but about different layers of meanings. Interior spaces
can be associated with different functional activities and values which
may form a rich environment and cannot be understood by just watching
‘photorealistic’ representation instead ‘imbuing’ the place. For a
better understanding and experience in a virtual design environment the
most engaging environment is required, which may not necessarily be the
most graphically realistic environment.

Visualization Issues

Despite
of comparable technical research (Strothotte & Schlechtweg 2002)
within non-photorealistic rendering (NPR), research doesn’t exist in
evaluating psychological knowledge regarding its effect on human
cognition and perception in interior design presentations. While the
Photorealistic image is defined by the singular principle of appearing
as realistic or ‘life-like’ as technologically possible, the Non- Normal 0 photorealistic
image is virtually infinite and artistic and appears to have variety of
styles (Harper, 2003).  The visual flexibility of Non-photorealistic
holds inherent, though still undefined, potential to influence viewer
responses in a variety of manners.

Conclusions

Non-photorealistic
renderings (NPR) have long proven useful in the fields of architecture
and urban planning: presentation techniques initiated by the Berkeley
Environmental Simulation Laboratory (Appleyard & Craik 1978) have
been designed to improve user needs when viewing planning alternatives.
Additionally, communication between experts and laymen has also
developed due to improvements in CAD, visualization, and simulation
(Linneweber 1993). In terms of laymen—citizens, investors, and future
users, participatory designs must facilitate interactions as well as
basic design understanding.

Schumann et al. (1996)
demonstrated that Non-photorealistic renderings (NPR sketch-rendered
design qualitatively improves the dialogue between architects and
clients, in contrast with dialogues elicited from Photorealistic
renderings (PR) images. Psychologically, sketch-rendered designs
maintain different affordances (Gibson 1977; Munz 1989), wherein
sketched images appear preliminary, unfinished, and therefore open to
change. Thus, the client is more likely to consider and suggest changes
to the design. NPR can also be employed to guide behavior. Halper et al. (2003)
demonstrates that increased levels of detail can effectively influence
both navigation and exploration behaviors, wherein subjects asked to
choose a path to explore or reach a goal in the distance tend to select
the path with the higher levels of detail PR images. Potentially,
subjects view in an increased level of detail PR is more interesting
for exploration, relative to lower level of detail NPR