CAVE  as it can be seen from the ouside. You can see the user inside wearing special 3D goggles that allow him visualising the projections that are performed onto the walls and floor. The sensation is so real that you can easily collide with the walls since they "disappear" from the environment. (Click on the image to enlarge it) Courtesy of Pere Brunet/CRV

Two weeks ago I had the opportunity of being a visitor to the “Centre de Realitat Virtual de Barcelona” (CRV), one of most advanced Virtual Reality Centres of Europe and the only one in the south of Germany that owns a CAVE system for collaborative design applications. CRV is a centre created 50% by Gedas a company of the VolksWagen group and (the other 50% by) the Universitat Politécnica de Catalunya. 

According to Pere Brunet, manager of CRV, who was kind enough to let me interview him (see the next issue of Inf@Vis!), Virtual Reality is a kind of digital representation of 3D Geometry models that has to accomplish three fundamental requirements:

• Sensory and 3D immersion.
  
  Sensory and 3D immersion means that virtual reality intends to substitute our perception, bound to the real world, for another perception generated by computer that nowadays basically affects our vision and hearing but is beginning to be completed with tactile sensations as well. 
  
  The 3D part of the immersion is obtained by offering each eye a slightly different computed image taking into account the separation between our eyes and our perspective, what’s called a stereoscopic projection. 
  
• Real time navigation.
  
  Real time navigation refers to the possibility of moving at will through the virtual environment and explore it as we wish.
  
• Implicit interaction.
  
  Implicit interaction implies that the computer knows our position and the orientation where we are looking at so it can consequently modify the perspective projection. This way if we bend down in order to look at a detail of the lower part of, let’s say, a steering wheel, what we’ll see is exactly the same and with the same perspective as if we had bent down in reality. When we stand up again, we’ll see it again as if we were standing up in the real world. 

Interior of a supertanker in the design stage. Once immersed in it you can navigate through it, inspect the rooms and test the best disposition of the pipes, etc.  This is a n example of collaborative design, where several people can stand virtually in it and discuss aspects of the design without having to go beyond the CAD layout.

Virtual Endoscopy of a human colon made by modeling the data resulting of an Computerised Axial Tomography. This allows you to explore the interior of the colon without the boring associated to traditional endoscopy and with the advantages that "being there" gives to you. In particular you can see in any direction, you can move and navigate, you can stop and magnify.     The experience is really impressive giving you an idea of the possibilities of this technique in health care.

Images Courtesy of Pere Brunet/CRV  (Click on the image to enlarge it)

Generally virtual reality is associated with leisure and entertainment applications, but during my visit I had the opportunity to walk through the insides of a supertanker that only exists in the computer, testing where the pipes produce problems of circulation or where collisions can occur between them. 

I was also on top of the tower of an oil refinery and could enter in a new model of a car, recently launched onto the market.

At CRV the industrial applications share the leading role with the medical ones. Modelling a heart with health problems that can lead the patient to a heart attack or preparing surgical intervention by means of virtual interaction with the organ to operate are just a few of the applications under research. 

Remarkably interesting in this field is the training of surgeons and physicians in general that can rehearse in a simulated environment without danger for the (virtual, of course) patient…

Unlike augmented reality, which was already mentioned in issue number 11, where you “don’t let the world out of your sight”, virtual reality isolates the user from the real world. This allows you to completely substitute the real experience for one of a synthetic nature, in which the participants can be in different continents, performing cooperative design tasks and, thus, avoiding the building of costly prototypes or preparing a specially difficult surgical operation.

Nevertheless Virtual reality is costly in terms of computer time and also in money. The computer that feeds CRV’s CAVE is a parallel system that works with 16 central processing units and has a cost that exceeds well over one million Euros, and even with this powerful computer, some extremely complex and realistic simulations produce a slightly jerky movement.

For these reasons these types of installations are fundamental in order to offer the possibility of bringing these costly technologies to companies, hospitals and technologic centres.

Nevertheless the future promises to change noticeably in a not too distant time horizon, as we’ll see in the next issue, that will present the interview that Pere Brunet was kind enough to have with us.

Links of this issue: