fishwick@fish.cis.ufl.edu (Paul Fishwick) (07/03/90)
This is in response to some of Peter Leaback's comments about the relationships between virtual reality and computer simulation. In short, I believe that simulation and virtual reality have strong interconnections in that people creating a simulation model will want to use many of the input devices and environmental/behavioral factors developing within the area of virtual reality (i.e. the data glove, body suits, helmet mounted displays). There are many exciting possibilities for research in combined simulation modeling while taking into account human factors and research in virtual reality. The relationship between virtual reality and simulation can be best seen by seeing the different emphasis: SIMULATION: Emphasis is on modeling and analysis of time dependent complex phenomena (real or imaginary). VIRTUAL REALITY: Emphasis is on human factors and psychological effectiveness. Here are some comments (below).... Paul Fishwick U. of Florida --------------------------------------------------------------- >From: peterl@ibmpcug.co.uk (Peter Leaback) Message-ID: <9006221738.AA20908@ibmpcug.CO.UK> >>I know this is a reply to an old message, but here goes... >>What is the difference between a virtual reality and a simulation? My >>answer is consistency. >>A stick model of a water molecule is a simulation of a real water >>molecule, but if you jump into a swimming pool full of stick water >>molecules, you won't get wet. The stick water molecules have many >>inconsistances compared to real molecules, so when one trys to interact >>the stick molecules with real ones, you have problems. >>But if a man made up of stick model molecules jumps into that same >>swimming pool, he WILL get wet. The issue of "reality" is a function of the fidelity of input and output devices. One is, in effect, trying to simulate an environment, real or otherwise. >>Saying that a global weather simulation is also a virtual reality is >>*useless*, because the whole point of writing a global weather simulation >>is to extract information to compare with the real world.So the global >>weather simulation will *always* be thought of as a simulation. Simulation and virtual reality are not at odds -- Simulationists can *use* technologies within virtual reality to create better simulations. In addition -- a computer simulation need not be of a "real" physical phenomenon. A simulation can define a model of some process, possibly unrealistic. The output of the simulation is then validated against data of some sort. We can see, then, that one can define simulations not only of physical systems, but also of mental models (in AI) and futuristic galactical adventures. The validation of science fiction scenarios usually involves face validation where a model is good if it generates greater degrees of interest from players/audience. Simulation methods in modeling and analysis are useful when one is trying to model time varying, complex systems (real or otherwise). Paul Fishwick University of Florida
steve@titan.tsd.arlut.utexas.edu (Steve Glicker) (07/04/90)
In article <23731@uflorida.cis.ufl.EDU> fishwick@fish.cis.ufl.edu (Paul Fishwick) writes: >From: peterl@ibmpcug.co.uk (Peter Leaback) Message-ID: <9006221738.AA20908@ibmpcug.CO.UK> >>What is the difference between a virtual reality and a simulation? A good question. >>My answer is consistency. ??? >>A stick model of a water molecule is a simulation of a real water >>molecule, but if you jump into a swimming pool full of stick water >>molecules, you won't get wet. The stick water molecules have many >>inconsistances compared to real molecules, so when one trys to interact >>the stick molecules with real ones, you have problems. >>But if a man made up of stick model molecules jumps into that same >>swimming pool, he WILL get wet. Simulations are usually intended for a purpose. Stick water molecules are not intended for this purpose. This example simply illustrates the incorrect use of stick water molecules. The stick water molecule is not invalid for its intended purpose. Is is usually not wise to examine a simulation model without regard to its purpose. > Simulation and virtual reality are not at odds I agree. -- Steven Glicker Applied Research Laboratories The University of Texas at Austin (steve@titan.tsd.arlut.utexas.edu)
peterl@ibmpcug.co.uk (Peter Leaback) (07/11/90)
Steve Glicker said, >Simulations are usually intended for a purpose. Stick water molecules >are not intended for this purpose. This example simply illustrates >the incorrect use of stick water molecules. The stick water molecule >is not invalid for its intended purpose. > >Is is usually not wise to examine a simulation model without regard >to its purpose. This is my exact point, a simulation model is only designed to function with a limited domain.Taken out of this domain, and the simulation ceases to act correctly. But a virtual reality *can't* be taken out of the context it was intended for. This is because all influences on the virtual reality keep the world consistent. If a reference to mass has been made about an object then all objects in the virtual reality must be assigned a mass also. An input device to this VR must give force feedback if one wants to interact with any object.This is because without force feedback, an inconsistency has been created between objects and that input device. Paul Fishwick said, >In addition -- a computer simulation need not be of a "real" physical >phenomenon. A simulation can define a model of some process, possibly >unrealistic. The output of the simulation is then validated against >data of some sort. We can see, then, that one can define simulations >not only of physical systems, but also of mental models (in AI) and >futuristic galactical adventures. I agree, simulations and virtual realities are not restricted to a reality similar to our own.If an analog to hands, eyes, mass, light etc can be found in "mental models" then a virtual reality of "mental processes" can be created. >SIMULATION: Emphasis is on modeling and analysis of time dependent >complex phenomena (real or imaginary). >VIRTUAL REALITY: Emphasis is on human factors and psychological >effectiveness. I feel your view is the result of the complexity of building virtual reality I/O. VR research at the moment is focused on building input/output devices, they are complex to build and use technologies that are still in their infancy. This does not mean that they are the underlying principal of VR's, they are the _effect_ of the underlying principlals. >The issue of "reality" is a function of the fidelity of input >and output devices. I disagree, the fidelity of a head mounted VDU does not effect the validity of the virtual reality it is interfacing with.A low resolution display can be thought of as an eye with a small number of rods and cones. Pete Leaback. P.S. I apologise if this message takes a while to be posted, my original message took 3 weeks to appear. -- Automatic Disclaimer: The views expressed above are those of the author alone and may not represent the views of the IBM PC User Group. -- --