3.4.1. Advanced flight simulator of Boeing 777: (a) outside view, (b) inside view (from [Atla95]). 

Context in source publication

Context 1

... applied as a teleoperating and collaborative medium, and of course in the entertainment area. For a long time people have been gathering a great amount of various data. The management of megabytes or even gigabytes of information is no easy task. In order to make the full use of it, special visualization techniques were developed. Their goal is to make the data perceptible and easily accessible for humans. Desktop computers equipped with visualization packages and simple interface devices are far from being an optimal solution for data presentation and manipulation. Virtual reality promises a more intuitive way of interaction. The first attempts to apply VR as a visualization tool were architectural walkthrough systems. The pioneering works in this field were done at the University of North Carolina beginning after year 1986 [Broo86], with the new system generations developed constantly [Broo92b]. Many other research groups created impressive applications as well – just to mention the visualization of St. Peter Basilica at the Vatican presented at the Virtual Reality World ’ 95 congress in Stuttgart or commercial Virtual Kitchen design tool. What is so fantastic about VR to make it superior to a standard computer graphics? The feeling of presence and the sense of space in a virtual building, which cannot be reached even by the most realistic still pictures or animations. One can watch it and perceive it under different lighting conditions just like real facilities. One can even walk through non-existent houses – the destroyed ones (see fig. 1.3.2.1) like e.g., the Frauenkirche in Dresden, or ones not even created yet. Another discipline where VR is also very useful is scientific visualization. The navigation through the huge amount of data visualized in three-dimensional space is almost as easy as walking. An impressive example of such an application is the Virtual Wind Tunnel [Brys93f, Brys93g] developed at the NASA Ames Research Center. Using this program the scientists have the possibility to use a data glove to input and manipulate the streams of virtual smoke in the airflow around a digital model of an airplane or space-shuttle. Moving around (using a BOOM display technology) they can watch and analyze the dynamic behavior of airflow and easily find the areas of instability (see fig. 1.3.2.2). The advantages of such a visualization system are convincing – it is clear that using this technology, the design process of complicated shapes of e.g., an aircraft, does not require the building of expensive wooden models any more. It makes the design phase much shorter and cheaper. The success of NASA Ames encouraged the other companies to build similar installations – at Eurographics ’ 95 Volkswagen in cooperation with the German Fraunhofer Institute presented a prototype of a virtual wind tunnel for exploration of airflow around car bodies. Other disciplines of scientific visualization that have also profited of virtual reality include visualization of chemical molecules (see fig. 1.3.2.3), the digital terrain data of Mars surface [Hitc93] etc. Augmented reality (see fig. 1.3.2.4) offers the enhancement of human perception and was applied as a virtual user ’ s guide to help completing some tasks: from the easy ones like laser printer maintenance [Brys92c] to really complex ones like a technician guide in building a wiring harness that forms part of an airplane ’ s electrical system [Caud92]. An other example of augmented reality application was developed at the UNC: its goal was to enhance a doctor ’ s view with ultrasonic vision to enable him/her to gaze directly into the patient ’ s body [Baju92]. In modeling virtual reality offers the possibility of watching in real-time and in real-space what the modeled object will look like. Just a few prominent examples: developed at the Fraunhofer Institute Virtual Design (see fig. 1.3.3.1) or mentioned already before Virtual Kitchen – tools for interior designers who can visualize their sketches. They can change colors, textures and positions of objects, observing instantaneously how the whole surrounding would look like. VR was also successfully applied to the modeling of surfaces [Brys92b, Butt92, Kame93]. The advantage of this technology is that the user can see and even feel the shaped surface under his/her fingertips. Although these works are pure laboratory experiments, it is to believe that great applications are possible in industry e.g., by constructing or improving car or aircraft body shapes directly in the virtual wind tunnel! The use of flight simulators has a long history and we can consider them as the precursors of today ’ s VR. First such applications were reported in late 1950s [Holl95], and were constantly improved in many research institutes mainly for the military purposes [Vinc93]. Nowadays they are used by many civil companies as well, because they offer lower operating costs than the real aircraft flight training and they are much safer (see fig. 1.3.4.1). In other disciplines where training is necessary, simulations have also offered big benefits. Therefore they were prosperously applied for determining the efficiency of virtual reality training of astronauts by performing hazardous tasks in the space [Cate95]. Another applications that allow training of medicine students in performing endosurgery [McGo94], operations of the eye [Hunt93, Sinc94] and of the leg [Piep93] were proposed in recent years (see fig. 1.3.4.2). And finally a virtual baseball coach [Ande93] has a big potential to be used in training and in entertainment as well. One can say that virtual reality established itself in many disciplines of human activities, as a medium that allows easier perception of data or natural phenomena appearance. Therefore the education purposes seem to be the most natural ones. The intuitive presentation of construction rules (virtual Lego-set), visiting a virtual museum, virtual painting studio or virtual music playing [Loef95, Schr95] are just a few examples of possible applications. And finally thanks to the enhanced user interface with broader input and output channels, VR allows people with disabilities to use computers [Trev94, Schr95]. Although the goal of telerobotics is autonomous operation, a supervising human operator is still required in most of cases [Bola93]. Telepresence is a technology that allows people to operate in remote environments by means of VR user interfaces (see fig. 1.3.5.1 and 1.3.5.2). In many cases this form of remote control is the only possibility: the distant environment may be hazardous to human health or life, and no other technology supports such a high level of dexterity of operation. Figure 1.3.5.2 presents an example of master and slave parts of a teleoperating system. The nanomanipulator project [Tayl93] shows a different aspect of telepresence – operating in environment, remote in terms of scale. This system that uses a HMD and force-feedback manipulation allows a scientist to see a microscope view, feel and manipulate the surface of the sample. As the same category, the mentioned already before eye surgery system [Hunt93], might be considered: beyond its training capabilities and remote operation, it offers the scaling of movements (by factor 1 to 100) for precise surgery. In fact it may be also called a centimanipulator. Network based, shared virtual environments are likely to ease the collaboration between remote users. The higher bandwidth of information passing may be used for cooperative working. The big potential of applications in this field, has been noticed and multi-user VR becomes the focus of many research programs like NPSNET [Mace94, Mace95b], AVIARY [Snow94a] and others [Fahl93, Giga93b, Goss94]. Although these projects are very promising, their realistic value will be determined in practice. Some practical applications, however, already do exist – just to mention a collaborative CO-CAD desktop system [Gisi94] that enables a group of engineers to work together within a shared virtual workspace. Other significant examples of distributed VR systems are training applications: in inspection of hazardous area by multiple soldiers [Stan94] or in performing complex tasks in open space by astronauts [Cate95, Loft95]. Constantly decreasing prices and constantly growing power of hardware has finally brought VR to the masses – it has found application in the entertainment. In last years W-Industry has successfully brought to the market networked multi-player game systems (see fig. 1.3.7.1). Beside these complicated installations, the market for home entertainment is rapidly expanding. Video game vendors like SEGA and Nintendo sell simple VR games, and there is also an increasing variety of low-cost PC-based VR devices. Prominent examples include the Insidetrak (a simplified PC version of the Polhemus Fastrak), i-glasses! (a low cost see-through HMD) or Mattel PowerGlove. Virtual reality recently went to Hollywood – Facial Waldo TM and VActor systems developed by SimGraphics allow to “ sample any emotion on an actor ’ s face and instantaneously transfer it onto the face of any cartoon character ” [Dysa94]. The application field is enormous: VActor system has been used to create commercial impressive videos with ultra low cost: USD10 a second, where the today ’ s industry standard is USD1,000 a second. Moreover, it may be used in live presentations, and might be also extended to simulate body movements. VR requires more resources than standard desktop systems do. Additional input and output hardware devices and special drivers for them are needed for enhanced user interaction. But we have to keep in mind that extra hardware will not create an immersive VR system. Special considerations by making a project of such systems and special software [Zyda93b] are also required. First, let us have a short look at the basic components of VR immersive ...