But we believe, in a near future, this line will become a circle, with the two extremes to be overlapped in a single point. Currently RE and VE are recognized to be the extremes of a continuum line where Augmented Reality (AR) and Augmented Virtuality (AV) lie too, according to the proposition of Milgram & Kishino (1994, see Figure 1). We can expect from the future weaker and weaker boundaries between Real Environment (RE) and Virtual Environment (VE). In particular an novel authors’ patented technology is presented. This chapter covers the aspects related to the Visualization tools for VR, talking of their requirements, history, evolution, and latest developments. So here we present and discuss new technologies and new trends in Virtual Reality Visualization of 3D Scenarios, also reporting our personal research and applications, especially devoted to new holographic systems of projection. But this cannot be considered as a real VR experience. Apple’s QuickTime VR, for example, uses photographs for the modelling of three-dimensional worlds and provides pseudo look-around and walk-trough capabilities on a graphic monitor. So, VR is named also for variations which include mouse-controlled navigation “through” a graphics monitor, maybe with a stereo viewing via active glasses. Today, the term VR is also used for applications that are not properly “immersive”, since the boundaries of VR definition are within a certain blur degree. That’s the way to realize the longed “real” immersive experience, even going beyond mere images visualized on a screen, toward ones that we can interact with and walk-throughor navigate-through(the so called Princess Leia effectfrom the Star Warsmovie) because no solid support for projection is necessary. We are not thinking to the “standard” 3D representation furnished by flat monitors, but real new 3D Visualization which can occur in a three-dimensional room environment, furnished by dedicated equipment, which allows to visualize any scenario from any perspective. The requirement for 3D Visualization in VR seems that can be now partially or, in some way, completely satisfied thanks to new possibilities offered by the latest technologies. In addition an interesting patented technology is described for which the screen is not made by a solid material as it usually occurs, so that the viewer can even walk-throughthe visualized scenario.
To this aim we report the most significant commercial products and the most relevant improvements obtained with research prototypes for 3D Visualization in VR. The final goal is to furnish to the reader a complete panorama of the state of the art and of the realizations under development in the research laboratories for the future possibilities. This chapter describes the actual requirements for 3D Visualization in VR, the current state and the near future of the new trends. In VR, a Visualization in three dimensions becomes more and more mandatory, since it allows more easily the humans to see patterns, relationships, trends. The current adoption of flat panel monitors which represent only the “illusion” of the depth, does not completely satisfy the requirement of an “immersive” experience. This can represent a limit or, even, a problem, due to the fact that human beings largely rely on Visualization, and the human reactions can be more appropriate in front of spatial, three-dimensional images, rather than to the current mainly adopted two-dimensional Visualization of scenarios, text and sketches. But while the Computational Technology experienced an exponential growth during the last decades (the number of transistors on an integrated circuit doubles approximately every 18 months according to the Moore’s law), the Technology devoted to Visualization did not catch up with its counterpart till now.
Since VR is basically a three-dimensional representation of a not real environment, mainly due to computer-generated simulation, Computation and Visualization are the key technologies to pay attention to. Therefore great efforts have been paid over time to the development of more and more realistic and sophisticated VR scenarios and representations. Virtual Reality (VR) is successfully employed for a real huge variety of applications because it can furnish major improvement and can be really effective in fields such as engineering, medicine, design, architecture and construction, education and training, arts, entertainment, business, communication, marketing, military, exploration, and so on.