From: akk@trantor.informatik.uni-erlangen.de (Andy Klingler)
Subject: Re: Virtual Mars
Date: Thu, 17 Jan 91 21:54:58 GMT+1
Organization: CSD, University of Erlangen, Germany


In sci.virtual-worlds, article <14504@milton.u.washington.edu>
bungi@milton.u.washington.edu (Timothy Wood) writes:

[...]
> To obtain an even slightly usefull picture, let's say
> that we use 8 bits per square centimeter.  The appoximate size of the file
> would be something like 116E15 bits.  Too be _fun_ we would need to be
> working on a much smaller scale, say square millimeters.  At this small of
> a scale, the slight fractal nature of the surface would cause the area
> mapped be be far greater than the spherical approximation, and the
> spherical approximation _ain't_ small ( 'bout 11.6E18 bits ).
>         If this were a mere pleasure simulation, one could easily use a
> rougher scale and make whatever random bumps we wanted.
>
>         My question is this, is it possible to access and image this much
> data at a rate that would be necessary for a good graphical simulation?
>

In BYTE 11/90 was an article about holographic storage devices.
They claim in future these devices will be able to store more than
100 GByte per module at transferrates of more than 1 TByte/s (the prototypes
have 200 MByte - 2 GByte at 100-800 MByte/s).
So you would still need over 10 millon of those giant modules.
Anyway I guess 8 bits per surface point are far to less to give you any
usefull information. A datastructure per point would more look like this:

height        - many bits, depends on resolution and min/max height of the
                surface
spectral data - such as red, green, blue, infrared etc.; typically 8 bits
                each
... whatever you can think of

This way you get a *lot* more than 8 bits/sampled point.
I don`t think we will be able to handle this amount of data in the near
future. Besides this, I don`t know of a method to obtain the above data
at the mentioned spacial resolution.
---
Andreas Klingler
akk@trantor.informatik.uni-erlangen.de
         If you have enough patience, everything can be simulated
                               Marvin Minsky