Level of realism (detail)

Some time ago, Mandelbrot (1983) suggested that the fundamental problem is the digital representation of natural phenomena as ‘clouds are not spheres, mountains are not cones, coastlines are not circles, and bark is not smooth, nor does lightning travel in a straight line’. Seven years later, Hall (1990) introduced another definition of ‘realistic’; ‘creating an experience that is indistinguishable from the real experience; generating the same stimulus as the real environment; generating the same perceptual response as a real scene; creating the impression of a real scene’.

In 1999, Lange’s research, Degree of Realism argued that the impression of realism did not necessarily require correct imagery in terms of geometric detail as long as the general behaviour was reasonable; that high image complexity is primary in creating the perception of realism; that subtle shading and surface detail were key in creating the perception of realism.

However, level of realism needs to be distinguished between photo-realism and immersive experience. Since this thesis is divided into two visualisation categories; photo

manipulation and three dimensional media, the realism from rasterised image-based data is referred to as photo-realistic; whereas, in three dimensional media based on three

dimensional geometries such as pre-set path simulation, real time rendering and virtual reality meant 3D immersive realism.

The definition of realism is generally regarded as ‘Creating an experience that is indistinguishable from the real experience; generating the same stimulus as the real environment; generating the same perceptual response as a real scene; creating the

impression of a real space’ (Hall, 1990, page 191); realism is always an issue in computer visualisation.

Similarly, there is research raising technical issues on virtual reality (Doyle et al., 1998). In particular, they explored the subject in accordance with the Internet technology and the analysis of virtual reality as a flexible tool of information sharing in the context of planning. This research applies document and practical survey methodology to answer research questions; the review of capabilities of the technologies and how they can be applied in the field of planning and the design of urban environments.

On the other hand, Bishop and Rohmann (2003) focused on pre-set simulations.

Simulations with high levels of detail were compared with real environments for subject responses. This research found that even detailed and time consuming computer simulation does not necessarily generate the same responses as the corresponding real environment. However, differences between day and night conditions are mostly the same in the

simulated as in the real environment, and the realism ratings of the viewers were generally encouraging. The findings elucidate where further development and evaluation are

warranted.

The actual limitation to resolution of the approach to visualisation can be determined by hardware (processing speed, memory or graphical capabilities), software or data (Brodlie et al., 2002). However, in the light of affordability, high levels of detail tending towards real world would not always be the prime target for computer visualisation in planning. Visualisation preparers and planners generally compromise and agree on an appropriate balance between levels of detail and production cost. This fact was supported by research (Appleton, 2001) pointing out that high degree of realism might actually prove distracting in some ways. In addition, the level of detail could be decided by the purpose and use of the model, which can be focused on certain elements in visualisation (Appleton and Lovett, 2003, Lange, 1999).

Even though visualisation technology has always aimed at approaching the real world, Vince (1998) and Whyte (2002) claimed that the virtual model might never match the real world because of substance beyond the technology. For instance, a real-time model would not reflect abundant atmospheric circumstances in the real world such as clear, cloudy, rainy and windy conditions. Moreover, causality in every action and reaction, and physics in the real world cannot be replaced with computer-generated models (Cavazza, 2004).

1. There is an issue relating to the precise relationship that is claimed between a given simulation and the source reality it purports to represent. In effect, this poses the questions: what is the virtual component of any given virtual reality and what is the real? Despite considerable rhetoric to the contrary, the answer to this basic question is often far from self-evident.

2. A number of navigational issues persist in multi-dimensional, complex spaces. Which users and which applications might benefit from limiting users in a virtual landscape to real-world navigation and movement?

Appleton and Lovett (2003) investigated the paradigm of the decision making support provided by visualisation in planning in order to seek a sufficient level of realism. But it sets up different landscape elements such as ground surface, shadows, buildings, sky and human elements of familiarity and experience. Then, it provides three different views with different composition of those elements and assesses each with a scoring system. It is found that the results indicate that not all elements of a visualized scene are of equal importance in helping viewers to image the landscape being portrayed and that effort may be best directed towards improving the realism of the ground, including vegetation, and especially in the foreground.

The sufficient level of realism has also been researched (Lange, 1999). With similar methods, Lange carried out an experiment on the region of Schwyz and Ingenbohl- Brunnen in Central Switzerland. Based on key elements, 90 images were prepared

depicting the virtual landscape of the site. Three of the images were photographs from the three different viewpoints (a background, middle ground, and foreground scenes). Another 86 images were corresponding computer-generated images with different representation levels. The final image was a composite of photo foreground and virtual background. The

different representation levels had been prepared on the basis of four elements: terrain, buildings, single trees, and forest.

The test set was evaluated by 75 test persons, consisting of experts, lay persons, local experts, and local lay persons. The results showed that the most important variable positively contributing to the degree of realism was the terrain with the draped high- resolution aerial ortho-photo. Second most important was the variable buildings. The evaluation was significantly influenced in a positive way if texture-mapped built-form was displayed.

Brodlie et al. (2002) raised the issue of accessibility in virtual reality. Virtual reality simulations could be prepared using an open standard, such as VRML or Java, rather than limited through the use of proprietary software. Therefore there are a number of

commercial issues and technological considerations ranging from the restraints inherent in a current hardware and delivery strategies through to the thorny issue of technological determinism.

On the other hand, Dykes (2000) explored that 360 degree panoramic imagery is used as a means of representing geographic information in a visualisation context. He particularly pointed out that the software map presented contains a degree of realism, was inherently spatial and provided an excellent means of synthesising information from a whole range of traditional and novel spatial data types. It was also suggested that the architecture and computer map presented in the research offered a flexible, extendable and distributed spatial solution with high degree of realism and interactivity.

The meaning of realism in Dyke’s research above is photo-realism. However, in computer visualisation research, realism refers to the immersive level of detail. It is also

understandable that photo realism is less difficult to achieve compared to authorising three dimensional geometries. However, it is not actually three dimensional, but pseudo-three dimensional15 which is composed with a series of still images.

However, this research does not suggest any hierarchy of computer visualisation media, but proposes a clear understanding of media and its pros and cons.

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This is a term for three-dimensional visualisation without physical geometries. For instance, it includes photographic 3D such as QuickTime VR and Panoramic VR.

Salter et al. (2009) investigated the role of digital tools in a collaborative planning process. In particular, the research was to evaluate the effectiveness of a ‘digital workshop’,

combining the interactive community visualisation tool with the immersive lab facilities. They also suggested that there was a need to examine in greater depth how and when these tools might best be employed in collaborative settings.

Interestingly, the validity of images has been raised. Gower et al. (2000) explored an experiment of a GIS virtual tour which was designed for the interior of the Princess of Wales Conservatory, in the Royal Botanic Gardens, Kew. By recording a series of thirty one 360 degree; panoramas within the Conservatory, visual scenes were created to provide a virtual environment. Using photo stitching software, panoramas were created and

programming language Visual Basic 5.0 enabled the panoramas to zoom, pan, and selection of panoramas and zones. By employing the photograph based medium, the research finds that the use of panoramas proved to be a very effective method of capturing details, botanical scenes and internal architecture, while the map of geo-referenced

panorama locations provided a useful navigation tool. Therefore, Gower et al. concluded that they expected the use of this technology to grow rapidly.

Rather than authorising three dimensional geometries, the photo stitching technology is also recognised as an easy and effective way to create three dimensional models (Szeliski, 2006). For that reason, a number of software tools have been developed for this particular task of photo-editing easily and effectively at low costs.

There are a number of experts who already have indicated that 3D is real media which can change all our industries. In particular, real time virtual reality has been explored in the fields of design including architecture (Campbell and Wells, 1995). This research finds that both immersive and non-immersive virtual reality was useful in the design process.

Immersive VR offered the designer a better perception of space and the opportunity to see the design from the inside. At the scale of a person within the building, the designer was able to examine details and connections more intuitively with an easy-to-control viewpoint. Non-immersive VR, with a monitor and spaceball, offered higher resolution and higher frame rates, both of which became necessary as the model increased in complexity. The non-immersion offered easier and quicker manipulation of the viewpoint.

Realism of virtual landscape study was carried out by Lange (2001). Lange’s research found that approximately 75% of the persons assigned the highest possible value (very

high degree of realism) to one or more scenes of simulated landscapes. Moreover, the author suggests that in order to achieve an even higher degree of realism, more and very detailed three dimensional object data and accompanying texture information would be necessary.

On the other hand, the real-time simulations became more useful as a design tool as the level of detail of the model (colour, transparency, and geometric complexity) increased. However, the level of detail needed to be kept in check to keep the frame rate at an acceptable level. Although, more powerful geometry engines are continually being developed, it is unlikely that we will ever be satisfied with the level of detail that can be simulated in real time.

Nevertheless, two dimensional media offers a limited means of representing three

dimensional spaces. Three dimensional media enhance the perception of three dimensional spaces. Designers need a digital design medium which allows them immediate, direct, and more intuitive control over their three dimensional design and virtual reality can help. An inclusive, three dimensional, world building toolkit that matches the sophistication of today would supplement CAD software, but not replace other design media. It is only when such software has been developed that virtual reality can significantly enhance the design process (Campbell and Wells, 1995).

This technology is best known as video gaming in particular first person shooting. It has been most developed in the past decade including gaming engines and graphics. On the other hand, there remains a number of issues in implementing this technology in planning. For instance, collision handling has been investigated in the research by (Jacobson and Lewis, 1997) as the users’ point of view.

It is also debatable what sort of experience real time rendering technology can give to users. For example, users could navigate as walking through a virtual environment controlling both the speed and direction of walking. Furthermore, Jacobson and Lewis (1997) continued to explore three prototypical methods of collision handling in virtual reality: either the user goes through an object like a ghost, stops dead on contact, or slides around it. This research also concludes that by using mouse and screen, virtual environments become more affordable and accessible.

This emerging new technology is also explored (Bishop et al. 2001) for the assessment of path choices on a country walk. The paper includes the process of model building for a section of the Dee valley in northeast Scotland, the development of software to support interactive exploration. In addition, an experiment which was designed to answer some primary questions about validity and some secondary ones about local landscape preferences.

The final issue that needs to be highlighted is the lack of people in our often highly- sophisticated virtual simulations. Navigating a virtual construct can often be a costly and unsettling experience, yet the introduction of avatars and virtual inhabitants poses

considerable technical and representational challenges.