Can Virtual Reality Simulation Techniques Reshape the Future of Environmental Simulations?
By: Ayman H. Mahmoud
B.Sc. (Honours); M.Sc. (Cairo)
Doctoral Student, Department of Landscape, University of Sheffield,
Sheffield, S10 2TN, UK
This paper discusses the possibilities of applying Virtual Reality (VR) technology in environmental simulations for landscape design practice. It starts with the definition of VR as well as a background of its history and current achievements. Types and components of VR systems are described, and the procedure of synthetic construction of a virtual environment is explained. Having criticised traditional simulation techniques, the paper highlights the need to further development. A discussion of current attempts in incorporating VR in environmental design disciplines raises the question of appropriateness of the VR techniques in environmental simulations. A comparison between both immersive and non-immersive VR suggests an answer to this question. Types of non-immersive VR are discussed. The discussion recommends Desktop VR including VRML (Virtual Reality Modelling Language) as a possible and appropriate environmental simulation technique. This study concludes some potentialities, constraints and problems of this technique, and recommends future research efforts.
Virtual Reality- VRML - Environmental Simulation- Environmental Design
1. Introduction to Virtual Reality
Virtual Reality (VR) has received an enormous amount of publicity over the past few years. Potentials of VR applications have been realised in many disciplines. VR with its increasing dynamic, interactive and experiential characteristics becomes able to simulate real environments with various degrees of realism. Converging development in VR technology and Environmental Simulation techniques, as essential tools for environmental design, is the aim of this paper. There are a number of questions to be answered before introducing VR for environmental practitioners. What are the dimensions of this new technology? What are the possibilities of its contribution to environmental simulations? In other words, can it reshape the future of environmental simulations?
There is almost no standard definition to the term Virtual Reality. It has been defined it as the illusion of participation in a synthetic environment rather than external observation of such an environment. VR relies on three dimensional (3D), stereoscopic, head-tracked displays, and hand/ body tracking. VR is an immersive multi-sensory experience... (Gigante, 1993; Morgan & Zampi, 1995). Ervin (1997) has defined Virtual Reality as the simulated reality while Pimental & Teixeira (1995: xvii) explained Virtual Reality as a breakthrough technology that allows the person to step through the computer screen into a 3-D simulated world Regenbrecht & Donath (1997) have defined it as the component of communication which takes place in a computer generated synthetic space and embeds human as an integral part of the system
1.2 Historical Background
Roots of virtual reality began at 1962 with the Sensorama of Morton Heilig. At 1968 Ivan Sutherland described the head-mounted display which tracked the viewer and updated a graphic display. Military investigation during the cold war added numerous contributions to the field of Virtual Reality by development of flight simulators by the US Air Force. In 1984 NASA presented VIVED (Virtual Visual Environmental Display), and later the VIEW (Virtual Interactive Environment Workstation). (Gigante, 1993)
During the last 15 years, Virtual Reality was perceived as the 6th generation of computer evolution in which no barrier exists between the user and the machine. Further applications of Virtual Reality for public research began by the attempted by Brookes group of researchers in the mid 1980s who created a computer simulation of their research building's architectural proposal in both interiors and exteriors in order to explore it before construction. (Pimental & Teixeira, 1995: 60)
During the last decade there have been large-scale expansions in Virtual Reality applications in many disciplines. One of the reasons that VR has attracted so much interest is that it offers many benefits to many different areas of applications. Examples include operations in hazardous or remote environments, scientific visualisation, architectural visualisation, design, education and training, computer supported co-operative work, space exploration, and entertainment. (Gigante, 1993). In the last few years, there has been a practical need in many fields of creation to visualise ideas before establishment.
1.3 Types of Virtual Reality
Virtual Reality could be classified into two main types according to the degree of immersion and interface in the synthetic environment. The two types include Immersive and non-immersive Virtual Reality systems, Fig. (1). Morgan and Zampi (1995) have explained Immersive VR as an application in terms of quasi-physical experiences... In such experiences, fuller contact between users and the virtual space is maintained. Examples of these VR interactive experiences could be achieved by using data gloves and multi-media head mounted display devices (HMD). Non-immersive VR, e.g. screen based VR or Desktop VR, enables users through screen interface using special tools, e.g. eye glasses, to feel the simulated spatial environment. Current screen based VR systems include Division, and Superscape software.
Fig. (1) Types of Virtual Reality Systems
A recent emerging type of Virtual reality is the network VR. It is a result of the massive progress in the Internet and the World Wide Web in particular. Campbell (1996) indicated that the technology of Virtual Reality and the Internet continue to integrate, as the online culture is now the fastest growing demographic on the planet. The standard virtual reality format on the web is VRML (Virtual Reality Modelling Language) or (Virtual Reality Mark up Language) created by Silicon Graphics Inc..
VRML, as a phenomenon that is universally accessible, hyper-linked, is becoming common place on the World Wide Web. It is a file format for describing 3D interactive 3 dimensional virtual environments. It is capable of representing static and animated objects and it can have hyperlinks to other media such as sound, movies and images. (VRML 2.0, 1998)
1.4 Components of Virtual Reality system
Components of a virtual reality system include effectors, reality simulator, application, and geometry.
Effectors are any type of interface device that provides access to a virtual environment examples include head-mounted display devices, data gloves, 2d or 3d mice, 2d screens, and head phones.
Reality Simulator is the hardware that supplies the effectors with the necessary sensory (visual or acoustic) information depending on the degree of immersion needed, examples include Silicon Graphics Reality Engine workstations.
Application is the software that describes the context of the simulation. There is a wide variety of software depending on the system platforms including Intel PC, Silicon Graphics (SGI), and Sun platforms. An examples of Intel based PC software is Division (from AutoDesk).
Geometry is the information that describes the physical attributes of objects in the virtual environment. Basically geometry is built by CAD software. The most common 3D modelling CAD is AutoCAD from AutoDesk that runs on Intel based PC. CAD files can be exported to rendering and Virtual Reality authorising software on the form of DXF as a drawing interchange format.
1.5 Synthetic construction of Virtual environments
Construction of the virtual environment passes through three main phases: modelling, rendering, and real time interactive presentation using system effectors.
Modelling is the process of building the geometry and physical attributes of objects that constitute the virtual environment using CAD software Fig. (2). Sipes (1994) has described the difficulties of such a process that depends on the information database, and the computer hardware configuration.
Rendering: Grabowiski (1996) has described rendering as the process that includes applying texture maps, defining lighting parameters are defined. Time of rendering depends on quality of rendering, complexity of the model, and speed of computer hardware. Lindhult (1997) believed that guidelines for choosing the texture-input medium include quality, speed, versatility, and file size. He thought that quality depends on the output resolution required for presentation. Fig. (3)
Fig. (3) CAD 3-D model (Constructed by the author)
2. Virtual Reality in Environmental Simulations
To study how could Virtual Reality simulation techniques be incorporated in environmental simulation, it is important to outline the nature of environmental simulation, criticism of current environmental simulation techniques, and the requirement of the future technique.
2.1 Environmental Simulations: Definitions and types, and criticism
What is environmental simulation? Appleyard (1977) described it as an attempt to represent environmental reality He believed it can not produce reality as it is. Campbell & Davidson (1997) saw simulation media are used to generate, represent, communicate, and evaluate ideas pertaining to the content of any discipline. Generally it is defined as the family of techniques utilised for replicating, previewing, and anticipating- in the laboratory- everyday environments that have been built, modified, or actualised. (McKechnie, 1977) Fig. (4)
2.1.1 Why Environmental Simulation is important to be studied?
The importance of environmental simulation is being crucial for almost all environmental design professions for presenting simulations of reality to the observer (client) to predict his responses of the real situation. McKechnie (1977) thought simulation techniques are crucial to decision making process of environmental designers.
Simulated depictions of visual ideas have always been an important tool in landscape architecture. The potential realities contained within a designer's imagination have been revealed through models, maps, plans, etc. (Watzek & Ellsworth, 1994; Zube, Simcox, & Law, 1987)
Fig. (4) A typology of environmental simulation techniques (After McKechnie, 1977).
2.2.2 A typology of tools for architectural design practice.
The presentation of design projects involves both visual and verbal communication. According to McKechnie (1977), the typology of environmental simulations includes perceptual (experiential, concrete) and conceptual (abstract). Stea (1988) has suggested a subdivision of those types of simulations into participatory and non-participatory modes. (Lawrence, 1993; Stea, 1988). Booth (1983) suggested the question of how to integrate both the presentation media and the real media in landscape design. The problem is how to use a media to depict the idea of the design in a representative manner, and to simulate the design reality at the same time.
Traditional simulation techniques were subject to intensive studies, and were criticised as they lack some important features that affects their reliability in predicting the real environment, such as the depth of visual field and passive interactivity. Pomeroy et al. (1989) studied Photographs as a traditional simulation technique that have been used and recommended by most researchers examining public response to the aesthetics of landscape. A number of studies have concluded the need to a new experiential dynamic, perceptual simulation technique. (E.g., Appleyard & Craik, 1978; Balling & Falk, 1982; Bernalez et. al. 1988; Brush & Shafer, 1975; Burkhart & Fusco, 1997; Buyhof & Wellman, 1980; Calvin et al., 1972; Dunn, 1976; Fines, 1968; Herzog et al., 1977; Pearce & Waters, cited in Pomeroy et al., 1982; Pomeroy et. al., 1989; Shuttleworth, 1980; Zube, 1974; Zube et al., 1975). Some of these studies have provided a comprehensive review and severe test of the use of photographs as surrogates in landscape perception studies.
The emergence of new feasible computer simulation techniques makes it important to try to use then as new simulation techniques for environmental research and design. Since Virtual Reality is believed is ultimate computer medium for simulating reality, it became very important to study the possibilities of incorporating such a new technique in environmental research and design.
2.2 Advances of Virtual Reality in Environmental simulations: Attempts and problems:
Many attempts were made in discussing how to apply Virtual Reality in environmental design (Campbell, 1996; Campbell & Davidson, 1997Ervin, 1997; Gigante, 1993b; Grabowiski, 1996; Hall, 1993; Menoni & Vignati, 1993; Morgan & Zampi, 1995; Regenbrecht & Donath, 1997; Sipes, 1994; and Sipes 1996). Problems included difficulty of modelling natural irregular landscapes (Sipes, 1996); limitations of hardware performance (Campbell & Davidson, 1997; Rugenbrecht & Donath, 1997), and the need for physical constraints (Campbell, 1993; and Papper & Gigante, 1993). Most of these studies agree that Virtual Reality can be the future tool for environmental simulation.
2.3 Appropriateness of VR: A comparison between types of VR systems
The question is if Virtual Reality could be the future technique, then what type of Virtual Reality is the most appropriate for design practice? Pimentel & Teixiera (1995) tried to answer this question by discussing the factors that affect the feasibility of Virtual Reality. One major factor is cost. Until recently, Virtual Reality manipulation has been almost private for powerful high-end workstations like Reality Engine from Silicon Graphics. The problem is that it may be too expensive to be widely used outside large universities' labs. Most of the mentioned above studies used such expensive hardware. The question is how can ordinary environmental designers make use of Virtual Reality?, in other words is there an affordable Virtual Reality?
Fig. (6) Evolution of the two types of VR in UK (Loughborough, 1997)
In a survey conducted by the University of Loughborough into using VR in United Kingdom (between 1994 and 1997) it was clear that the majority of VR systems are desktop PC based (Fig. 6). Pimentel & Teixiera (1995) provided a proposal of a feasible Desktop Virtual Reality system, their studies are concluded in Table (1). It was suggested that a powerful PC based system could produce VR if we eliminate the need for a stereo-scopic system and use a mono-scopic system instead.
It may be important to mention here that at the beginning of 1998, a PC microprocessor produced by Intel (Pentium II 333 MHz) had an iCOMP Index 366 while Pimentel & Teixiera (1995) have made their estimations on a PC Intel microprocessor (Pentium 75 MHz) which had an iCOMP Index 67. (Intel, 1998, http://www.intel.com/procs/perf/icomp/index.htm).
Table (1) Relative Costs of System Components (Pimentel & Teixiera, 1995: 134)
It could be concluded that Desktop VR tend to be more appropriate in terms of affordability and possibility of wide use, if we are seeking the publicity of VR for a wide base of environmental designers. VRML could be suggested as a future Desktop VR simulation technique. VRML browsers, e.g., CosmoPlayer 2.0 from SGI, are available on the Internet for many different platforms. Enhancing handling and public access, VRML tends to be an appropriate VR in the near future.
3. Principles of the using Virtual Reality in Environmental Simulation
To create a virtual reality environmental simulation we should consider the elements of a Virtual Reality application including navigation, immersion, and interactivity. (Ervin, 1994; and Pimentel & Teixiera, 1995: 11) Advances in CAD software presented easy and efficient tools for geometry modelling as well as data transfer from CAD 3D drawings to a Virtual Reality standard format. Examples include ArchiCAD that supports Apple Computers QuickTime VR software. The client or user doesn't need to have ArchiCAD, but he can view the model by QuickTime VR using a standard mouse for navigation. They could help clients to understand the space. Adding the chat feature, a conversation can be done while exploring the design. (Novitski, 1996). Another example may be 3D Studio Max from AutoDesk which runs on Windows NT workstation on Intel based PC, it exports 3D meshes in standard VRML format. (Kinetex, 1998)
Danahy & Wright (1988) discussed principles of studying a built environment using 3D-computer simulation, however, their study was limited with available technology of 1988. General environmental design criteria include building mass, open spaces, transportation and pedestrian systems, and environmental issues. Building mass includes heights, views, form and texture, sunlight penetration, building and open space relationship, and ground floor uses. Open spaces includes number and location, sunlight in eastern open space, pedestrian activity areas, landmark focus, seasonal and daily activities, historical, geological and archaeological references, and seating. Vehicle pedestrian system includes parking, pedestrian routes, sidewalk needs, street furniture, access ramps, and bicycles and motorcycle parking. Environmental issues include sunlight analysis, wind analysis, and lighting and colour in masses and landscape.
3.1 Psychological Issues in Virtual Reality Design.
Like any kind of new technology, Virtual Reality application in environmental design has limitations. Because environmental design deals with people and environment, it is necessary to explore to psychological, behavioural, and social effects of the new technique.
Gigante (1993b) suggested a hypothesis that to predict social impact of VR, we should revise the historical development of both HCI (human computer interaction) and CG (computer graphics). Campbell (1996) thought that social relationships and interactions would be dramatically altered as the transfer of information and images comes to substitute the movement of mass. People may come to communicate with others around the world with a realistic medium. VR will serve to shift from personal to electronic communication. Principles of environment behaviour including cognitive maps and territoriality are well-researched areas that are fundamental to one's perception of space and place. Socio-cultural perceptions, symbolic meanings of form, and the degree to which the formal and metaphysical character of a space can influence one's mood or behaviour in a space are all issues that could emerge from the physical realm to the virtual one. (Campbell, 1996)
3.2 Presentation of Virtual Reality for lay people
How can environmental designers present their virtual reality to clients? Morgan & Zampi (1995) discussed this issue and concluded that VR offers new tools to the architect to use in most of various design stages. Through VR information, that is handled electronically, the client will need enough information set for both design and construction stages plus continued management after completion. VR can add the tools of being accessible to Architecture in design process.
Ervin (1994) added that computer representations of landforms have a long way to go before they reach the expressiveness of a sketch produced by an experienced landscape designer The need for landscape architects to maintain computer compatibility is getting more necessary.
Novitski (1996) indicated that VR could help clients to understand a project before it is built. This has always been one of the key challenges of the architect. The most effective techniques may be expensive and time consuming. Making use of the Internet, architects can upload frequently updated animations of the space on a private Web site, so clients can see them during the design progress.
4. Discussion: Reliability of Virtual reality Simulations as the Future Technique.
It may not be an exaggeration to say that using an appropriate Virtual Reality, with its potentialities in visualisation, can provide environmental designers with a new powerful tool to enhance the design process.
The new technique has the potential to enable designers to increase their imaginations by visualising their hidden intentions and thoughts. It can help both clients and users to understand what designers invent, hence to communicate easy with professionals. It may help those who work in construction to understand how proposals can work in real conditions. Using the Internet-based VR can make design process universal, as many designers can collaborate in one project regardless their place on the planet.
Clients and users can explore their buildings while they are at home using the Internet network or a CD-ROM. The promise of VRML is still not totally discovered and further research is still needed. As the VR technology develops, the interfaces will become more simplified, and VR will achieve its goal to become a transparent medium of communication (Campbell, 1996)
It is believed that using VR in design could be considered as a revolutionary progress, it could transfer designers from thinking in 2D, using pencils and paper, to thinking in 3D using data gloves and 3D mice. It is believed that it does make a difference to think with volumes and masses rather than lines and hatches. Architectural aided design software is evolving rapidly from 2D drafting to a 3D building simulators. The architect's ability to construct a virtual building on a desktop computer, to simulate the building's behaviour both before it is built and through its life cycle, may very well change the architects design thinking the fee structure and the relationship with the client, contractor as well as the community (Marlett, 1997)
Constraints are still strong enough not to increase the publicity of the new technique. Constraints like accuracy, hardware limitations, display resolution, and cost still act as barriers. It is, however, believed these barriers may very well vanish, as long as the research and industry in computer technology are still carrying on.
Imitating the complexity and randomness of nature is beyond the capabilities of traditional computer modelling, which mathematically defines simple geometric shapes, cubes, spheres and cylinders. The hard-edged outlines of such models are still too ill to model many natural features. (Sipes, 1994). It is important to understand these limitations when using VR as a simulation technique for a physical measurable environment.
Problems still facing environmental designers include lack of training to use latest software, and lack of standards and rules to control the output work of designers. Another problem could be the response of traditional designers who may not like to adapt their work to a new technique. Thompson (1998) thought that to gain confidence in simulation, we need to know the way it is built, and the steps creator took to build the image...
While there are numerous studies about traditional environmental simulation technique, research in incorporating Virtual Reality simulations still at its beginnings. There is a need to a systematic experimental research to prove the reliability and validity of the new technique.
Virtual Reality is considered one of the ultimate information visualisation tools. Progress in computer hardware and software offers more facilities for a wide variety of disciplines. Environmental designers are seeking for a new simulation technique that can help them to better perform their design processes and to bridge the gab between their imaginations and the presented drawings. It is believed that Virtual Reality could be the most suitable tool for designers to simulate their ideas. Computer tools are essential for most designers because of the increased flexibility they provide in the rest of the product development cycle. Working in 2D increases the cognitive load of designers forcing them to mentally reconstruct the 3D shape from 2D sections. As most good designers are visual 3D thinkers, a VR design environment can provide them with appropriate 3D design tools.
Virtual environments will have principles and rules as environments that exist in the physical world. Designs of virtual environments will require the expertise of environmental designers. Formal design characteristics like rhythm, scale, balance, and unity will be parts of design of a virtual environment.
It is not yet known what levels of accuracy, for VR simulations, are required to be considered a credible simulation. Further researches are needed to establish accuracy guidelines for designers. Further research is needed in the field of visual perception of the virtual environment. Systematic research is needed to prove the reliability and validity of the new technique.
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