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From: Greg M  Johnson
Subject: Starfield: pow(10,6) spheres or an isosurface?
Date: 26 Aug 2002 21:52:26
Message: <3d6adb5a$1@news.povray.org>
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?


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From: Timothy R  Cook
Subject: Re: Starfield: pow(10,6) spheres or an isosurface?
Date: 27 Aug 2002 00:35:42
Message: <3D6B019D.2030809@scifi-fantasy.com>
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)

-- 
Tim Cook
http://empyrean.scifi-fantasy.com
mirror: http://personal.lig.bellsouth.net/lig/z/9/z993126

-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GFA dpu- s: a?-- C++(++++) U P? L E--- W++(+++)>$
N++ o? K- w(+) O? M-(--) V? PS+(+++) PE(--) Y(--)
PGP-(--) t* 5++>+++++ X+ R* tv+ b++(+++) DI
D++(---) G(++) e*>++ h+ !r--- !y--
------END GEEK CODE BLOCK------


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From: Tim Nikias
Subject: Re: Starfield: pow(10,6) spheres or an isosurface?
Date: 27 Aug 2002 00:44:44
Message: <3d6b03bc$1@news.povray.org>
You can find this already somewhere on the net,
let me just see...

http://www.starbase1.co.uk/downloads.htm

Is what I found, but it's not what I was looking for.
I found a set of include files last year somewhere
where you could include well over 200.000
stars... A little searching on google should do the
job.

Regards,

Tim

--
Tim Nikias
Homepage: http://www.digitaltwilight.de/no_lights/index.html
Email: Tim### [at] gmxde

>
> 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)
>


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From: Ken
Subject: Re: Starfield: pow(10,6) spheres or an isosurface?
Date: 27 Aug 2002 00:49:39
Message: <3D6B059B.B7F56C54@pacbell.net>
Tim Nikias wrote:
> 
> You can find this already somewhere on the net,
> let me just see...
> 
> http://www.starbase1.co.uk/downloads.htm
> 
> Is what I found, but it's not what I was looking for.
> I found a set of include files last year somewhere
> where you could include well over 200.000
> stars... A little searching on google should do the
> job.

http://www.geocities.com/CapeCanaveral/Galaxy/8018/  ???

-- 
Ken Tyler


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From: Mike Williams
Subject: Starfield: pow(10,6) spheres or an isosurface?
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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From: Rafal 'Raf256' Maj
Subject: Re: Starfield: pow(10,6) spheres or an isosurface?
Date: 27 Aug 2002 02:04:49
Message: <Xns9277518B33AF7raf256com@204.213.191.226>
Mike Williams <mik### [at] econymdemoncouk> wrote in
news:Aj0### [at] econymdemoncouk 

> 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.

Please eamil it to me (pov### [at] raf256com) 

"Del And",0,39,19.70,+30,51,39.00,-0.091,
what exacly are this numbers - with can be used as <x,y,z> coordinates ?


-- 
#macro g(U,V)(.4*abs(sin(9*sqrt(pow(x-U,2)+pow(y-V,2))))*pow(1-min(1,(sqrt(
pow(x-U,2)+pow(y-V,2))*.3)),2)+.9)#end#macro p(c)#if(c>1)#local l=mod(c,100
);g(2*div(l,10)-8,2*mod(l,10)-8)*p(div(c,100))#else 1#end#end light_source{
y 2}sphere{z*20 9pigment{function{p(26252423)*p(36455644)*p(66656463)}}}//M


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From: Leroy Whetstone
Subject: Re: Starfield: pow(10,6) spheres or an isosurface?
Date: 27 Aug 2002 02:29:33
Message: <3D6B3796.38E491F8@joplin.com>
Greg M. Johnson wrote:
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?


i  should run faster


--
Have Fun!


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From: Timothy R  Cook
Subject: Re: Starfield: pow(10,6) spheres or an isosurface?
Date: 27 Aug 2002 02:51:41
Message: <3D6B217C.1020200@scifi-fantasy.com>
Rafal 'Raf256' Maj typed:
> Mike Williams <mik### [at] econymdemoncouk> typed:
>>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.
> Please eamil it to me (pov### [at] raf256com) 

Ditto on that.  (tim### [at] scifi-fantasycom)
Also a nice macro to convert from decl/ascension to XYZ...
tho the geocities pov include looks useful, too...

-- 
Tim Cook
http://empyrean.scifi-fantasy.com
mirror: http://personal.lig.bellsouth.net/lig/z/9/z993126

-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GFA dpu- s: a?-- C++(++++) U P? L E--- W++(+++)>$
N++ o? K- w(+) O? M-(--) V? PS+(+++) PE(--) Y(--)
PGP-(--) t* 5++>+++++ X+ R* tv+ b++(+++) DI
D++(---) G(++) e*>++ h+ !r--- !y--
------END GEEK CODE BLOCK------


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From: Timothy R  Cook
Subject: Re: Starfield: pow(10,6) spheres or an isosurface?
Date: 27 Aug 2002 02:54:58
Message: <3D6B2241.8000108@scifi-fantasy.com>
Timothy R. Cook wrote:
> Ditto on that.  (tim### [at] scifi-fantasycom)
> Also a nice macro to convert from decl/ascension to XYZ...
> tho the geocities pov include looks useful, too...

I take that back.  That geocities include file is damn cool.

-- 
Tim Cook
http://empyrean.scifi-fantasy.com
mirror: http://personal.lig.bellsouth.net/lig/z/9/z993126

-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GFA dpu- s: a?-- C++(++++) U P? L E--- W++(+++)>$
N++ o? K- w(+) O? M-(--) V? PS+(+++) PE(--) Y(--)
PGP-(--) t* 5++>+++++ X+ R* tv+ b++(+++) DI
D++(---) G(++) e*>++ h+ !r--- !y--
------END GEEK CODE BLOCK------


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From: Greg M  Johnson
Subject: Re: Starfield: pow(10,6) spheres or an isosurface?
Date: 27 Aug 2002 08:31:34
Message: <3d6b7126$1@news.povray.org>
"Mike Williams" <mik### [at] econymdemoncouk> wrote in message
news:Aj0### [at] econymdemoncouk...
>
> The next three numbers are hours, minutes, seconds
> of the Right Ascension.
>

I'm rendering an anim of spheres right now.  Since the anim involves the
travel of a spacecraft, I wanted a "3d" look to it, not merely white points
on a skysphere.


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