POV-Ray : Newsgroups : povray.general : Starfield: pow(10,6) spheres or an isosurface? : Starfield: pow(10,6) spheres or an isosurface? Server Time
5 Aug 2024 16:11:06 EDT (-0400)
  Starfield: pow(10,6) spheres or an isosurface?  
From: Mike Williams
Date: 27 Aug 2002 01:54:31
Message: <Aj071AA8Mxa9EwPu@econym.demon.co.uk>
Wasn't it Timothy R. Cook who wrote:
>Greg M. Johnson wrote:
>> I didn't quite like how the starfield pigments looked in a sky_sphere, so
>> I'm going to make my own.
>> 
>> Q: which will render faster,
>> i) pow(10,6) spheres, or
>> ii) an isosurface of say the f_noise3d at low threshold and a huge scale?
>
>Be a manly man, plot a few hundred actual stars' relative positions.
>(Actually I'd like to try that, I just need to get a nice 
>comma-delimited text file of their positions)

If you're serious about that, I can send you a list in this format

"Alpheratz",0,8,23.30,+29,5,26.00,-0.163,
"Caph",0,9,10.70,+59,8,59.00,-0.181,
"Eps Phe",0,9,24.70,-45,44,51.00,-0.181,
"Algenib",0,13,14.20,+15,11,1.00,-0.012,
"Iot Cet",0,19,25.70,-8,49,26.00,-0.036,
"Iot Scl",0,21,31.20,-28,58,54.00,-0.074,
"Bet Hyi",0,25,45.10,-77,15,15.00,0.324,
"Ankaa",0,26,17.00,-42,18,22.00,-0.396,
"Bet1 Tuc",0,31,32.70,-62,57,29.00,-0.054,
"Pi And",0,36,52.90,+33,43,10.00,-0.004,
"Del And",0,39,19.70,+30,51,39.00,-0.091,

Each line contains the star name (If no actual name, then the Flamsteed
letter and constellation. If no Flamsteed, then Henry Draper number. If
no HD then Hipparcos number). 

The next three numbers are hours, minutes, seconds of the Right
Ascension.

The next three numbers are degrees, minutes, seconds of the Declination.
(Note, only the degrees show the sign but you'll have to remember to
apply it to the degrees and seconds).

The final number is the base magnitude, which indicates the brightness
of the star.

I have such a list for all stars brighter than magnitude 7.5, that's
15654 stars. The file is about 668 Kb in size.

-- 
Mike Williams
Gentleman of Leisure


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