Chris Jeppesen <chr### [at] digiquillcom> wrote:
: I like to do astronomical (space probes in the solar system) raytracing.
: Unfortunaltely, the current version of Povray can't handle extremely large
: differences in numbers which are generated by this scenario.

  And it probably never will (at least until the hardware develops so far that
bigger floating point numbers (say... 1024 bits at least) can be used).

: I wish there were a program that can simultaneously handle:

  I don't think there's any program out there which can handle this. The
problem is not the software, but the hardware.
  Ok, it is possible for the program to use its own floating point numbers
at whatever precision it wants, but that would slow down the program
considerably. Using the FPU for floating point calculations is just too
much faster than using the CPU for the same task.
  (For example an addition of two floating point numbers take usually one
clock cycle of processor time using the FPU; the same addition made with
software and bigger floating point numbers will probably take tens of even
hundreds of clock cycles.)

: Any one know why this can't be done?

  As I said, the hardware, ie. the FPU can handle only limited sized
floating point numbers. In povray usually the 'double' type is used, which
means a 64 bits floating point number in most systems (PC, sparc, ...).
It is pretty accurate, but it starts to be more and more inaccurate when
we use values that are extremely large and extremely small at the same time.


-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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