POV-Ray : Newsgroups : povray.object-collection : The Bright Star Catalogue Server Time: 14 Dec 2018 00:41:30 GMT
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From: Cousin Ricky
Subject: The Bright Star Catalogue
Date: 8 Feb 2017 13:04:29
Message: <589b175d$1@news.povray.org>
I have extracted some of the data fields from the Yale Bright Star 
Catalogue and converted them to SDL.  This catalog contains all 
nighttime stars of magnitude 6.5 and brighter (roughly all nighttime 
stars visible to the naked eye), plus a few dimmer ones.  The 
BrightStar5 module includes more data fields than the include file 
Rarius published a while back, including catalog designations and color 
data.  Macros are included for star coloration and Bayer designation 
labels.  You can also seek individual stars by Bayer, Draper, Flamsteed, 
or SAO designations.

Rarius stated that the catalog is in the public domain.  I could not 
determine the intellectual property status from the published sources, 
and in the process of trying to find out, I ended up having a very nice 
phone conversation with one of the authors, Dr. Warren!

The 5th edition of the catalog, as it stands, is in a preliminary state. 
  (The primary author died in 2007.)  There is no projected date for 
final publication.

POV-Ray 3.7.1 beta 2 will crash hard with this module.  Think Bayer 
designations, and if you've been following p.beta-test, you'll know 
exactly why it crashes.  Some of the 3.7.1 alphas (including some 2015 
vintages) also crashed, but 3.7.0 works fine.  The latest master passes, 
so everything should be fine when beta 3 is released.

http://lib.povray.org/searchcollection/index2.php?objectName=BrightStar5&contributorTag=Cousin%20Ricky


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From: Paolo Gibellini
Subject: Re: The Bright Star Catalogue
Date: 8 Feb 2017 13:24:03
Message: <589b1bf3$1@news.povray.org>
Cousin Ricky wrote on 08/02/2017 14:08:
> I have extracted some of the data fields from the Yale Bright Star
> Catalogue and converted them to SDL.  This catalog contains all
> nighttime stars of magnitude 6.5 and brighter (roughly all nighttime
> stars visible to the naked eye), plus a few dimmer ones.  The
> BrightStar5 module includes more data fields than the include file
> Rarius published a while back, including catalog designations and color
> data.  Macros are included for star coloration and Bayer designation
> labels.  You can also seek individual stars by Bayer, Draper, Flamsteed,
> or SAO designations.
>
> Rarius stated that the catalog is in the public domain.  I could not
> determine the intellectual property status from the published sources,
> and in the process of trying to find out, I ended up having a very nice
> phone conversation with one of the authors, Dr. Warren!
>
> The 5th edition of the catalog, as it stands, is in a preliminary state.
>  (The primary author died in 2007.)  There is no projected date for
> final publication.
>
> POV-Ray 3.7.1 beta 2 will crash hard with this module.  Think Bayer
> designations, and if you've been following p.beta-test, you'll know
> exactly why it crashes.  Some of the 3.7.1 alphas (including some 2015
> vintages) also crashed, but 3.7.0 works fine.  The latest master passes,
> so everything should be fine when beta 3 is released.
>
>
http://lib.povray.org/searchcollection/index2.php?objectName=BrightStar5&contributorTag=Cousin%20Ricky
>

It seems very interesting.
I hope to see soon some examples,
Paolo


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From: omniverse
Subject: Re: The Bright Star Catalogue
Date: 8 Feb 2017 16:55:01
Message: <web.589b4c7ae3b4c4169c5d6c810@news.povray.org>
Cousin Ricky <ric### [at] yahoocom> wrote:
> I have extracted some of the data fields from the Yale Bright Star
> Catalogue and converted them to SDL.

Thanks Richard! Great way to use the data. All of it impressive work.

Bob


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From: Cousin Ricky
Subject: Re: The Bright Star Catalogue
Date: 19 Feb 2017 12:51:01
Message: <58a994b5$1@news.povray.org>
On 2017-02-08 09:08 AM (-4), Cousin Ricky wrote:
> POV-Ray 3.7.1 beta 2 will crash hard with this module.  Think Bayer
> designations, and if you've been following p.beta-test, you'll know
> exactly why it crashes.  Some of the 3.7.1 alphas (including some 2015
> vintages) also crashed, but 3.7.0 works fine.  The latest master passes,
> so everything should be fine when beta 3 is released.

POV-Ray 3.7.1 beta 3 works fine with this module.


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From: Cousin Ricky
Subject: Re: The Bright Star Catalogue
Date: 7 Dec 2017 22:39:40
Message: <5a29c32c$1@news.povray.org>
On 2017-02-08 08:08 AM (-5), Cousin Ricky wrote:
> I have extracted some of the data fields from the Yale Bright Star
> Catalogue and converted them to SDL. [snip]
>
>
http://lib.povray.org/searchcollection/index2.php?objectName=BrightStar5&contributorTag=Cousin%20Ricky

I have uploaded BrightStar5 version 1.1, which has indexes on the data 
arrays.  The seek macros run *much* faster now.


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From: Mike Horvath
Subject: Re: The Bright Star Catalogue
Date: 10 Feb 2018 02:27:58
Message: <5a7e58ae$1@news.povray.org>
On 2/8/2017 8:08 AM, Cousin Ricky wrote:
> I have extracted some of the data fields from the Yale Bright Star 
> Catalogue and converted them to SDL.  This catalog contains all 
> nighttime stars of magnitude 6.5 and brighter (roughly all nighttime 
> stars visible to the naked eye), plus a few dimmer ones.  The 
> BrightStar5 module includes more data fields than the include file 
> Rarius published a while back, including catalog designations and color 
> data.  Macros are included for star coloration and Bayer designation 
> labels.  You can also seek individual stars by Bayer, Draper, Flamsteed, 
> or SAO designations.
> 
> Rarius stated that the catalog is in the public domain.  I could not 
> determine the intellectual property status from the published sources, 
> and in the process of trying to find out, I ended up having a very nice 
> phone conversation with one of the authors, Dr. Warren!
> 
> The 5th edition of the catalog, as it stands, is in a preliminary state. 
>   (The primary author died in 2007.)  There is no projected date for 
> final publication.
> 
> POV-Ray 3.7.1 beta 2 will crash hard with this module.  Think Bayer 
> designations, and if you've been following p.beta-test, you'll know 
> exactly why it crashes.  Some of the 3.7.1 alphas (including some 2015 
> vintages) also crashed, but 3.7.0 works fine.  The latest master passes, 
> so everything should be fine when beta 3 is released.
> 
>
http://lib.povray.org/searchcollection/index2.php?objectName=BrightStar5&contributorTag=Cousin%20Ricky

> 

The fuzzy circles don't look so great. I don't know if anything can be 
done to improve them however. In video games, stars are often reduced to 
1 pixel. But I don't think in POVray there's an easy way to make a star 
exactly 1 pixel big. Maybe with some trigonometry?


Mike


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From: Bald Eagle
Subject: Re: The Bright Star Catalogue
Date: 10 Feb 2018 03:25:00
Message: <web.5a7e65bde3b4c4165cafe28e0@news.povray.org>
Mike Horvath <mik### [at] gmailcom> wrote:
But I don't think in POVray there's an easy way to make a star
> exactly 1 pixel big. Maybe with some trigonometry?

I worked that out obtain a constant-apparent-width cylinder for a bounding box,
and a Dupin cyclide for orbital trajectories.
Obtaining a constant 1-pixel width is pretty trivial with the orthographic
camera, since with the default camera, IIRC, 1 POV-unit = 1 pixel.


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From: Le Forgeron
Subject: Re: The Bright Star Catalogue
Date: 10 Feb 2018 18:41:25
Message: <5a7f3cd5$1@news.povray.org>
Le 10/02/2018 à 04:23, Bald Eagle a écrit :
> Mike Horvath <mik### [at] gmailcom> wrote:
> But I don't think in POVray there's an easy way to make a star
>> exactly 1 pixel big. Maybe with some trigonometry?
> 
> I worked that out obtain a constant-apparent-width cylinder for a bounding box,
> and a Dupin cyclide for orbital trajectories.
> Obtaining a constant 1-pixel width is pretty trivial with the orthographic
> camera, since with the default camera, IIRC, 1 POV-unit = 1 pixel.

not really.
Unless your default camera is
...
  up image_height*y
  right image_width*x
...
but that's not the camera you get from

camera{ orthographic }

|| up: 0.000, 1.000, 0.000
|| right: 1.330, 0.000, 0.000
|| location: 0.000, 0.000, 0.000
|| direction: 0.000, 0.000, 1.000


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From: Bald Eagle
Subject: Re: The Bright Star Catalogue
Date: 10 Feb 2018 22:15:01
Message: <web.5a7f6ebae3b4c4165cafe28e0@news.povray.org>
Le_Forgeron <jgr### [at] freefr> wrote:

> not really.
> Unless your default camera is
> ...
>   up image_height*y
>   right image_width*x
> ...
> but that's not the camera you get from
>
> camera{ orthographic }
>
> || up: 0.000, 1.000, 0.000
> || right: 1.330, 0.000, 0.000
> || location: 0.000, 0.000, 0.000
> || direction: 0.000, 0.000, 1.000

Well, then I guess I didn't remember correctly  ;)

I vaguely recalled this discussion:
http://news.povray.org/povray.advanced-users/thread/%3Cweb.5845a06cc97737fcc437ac910%40news.povray.org%3E/

So modifying that so Pixel "size" is described in POV-units, then we could have

#macro Zoom (PixelSize)
camera {
 orthographic
 location <0, 0, -PixelSize>
 look_at  <0, 0, 0>
 right (x*image_width )*PixelSize
 up    (y*image_height)*PixelSize
 }
#end


(I haven't entirely determined what the best camera-to-lookAt distance is to
avoid some weird things happening)


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From: Mike Horvath
Subject: Re: The Bright Star Catalogue
Date: 11 Feb 2018 00:56:46
Message: <5a7f94ce$1@news.povray.org>
I kinda wish there were a POV-Ray object that would be guaranteed to 
always be 1 pixel big.

Mike



On 2/10/2018 5:14 PM, Bald Eagle wrote:
> Le_Forgeron <jgr### [at] freefr> wrote:
> 
>> not really.
>> Unless your default camera is
>> ...
>>    up image_height*y
>>    right image_width*x
>> ...
>> but that's not the camera you get from
>>
>> camera{ orthographic }
>>
>> || up: 0.000, 1.000, 0.000
>> || right: 1.330, 0.000, 0.000
>> || location: 0.000, 0.000, 0.000
>> || direction: 0.000, 0.000, 1.000
> 
> Well, then I guess I didn't remember correctly  ;)
> 
> I vaguely recalled this discussion:
>
http://news.povray.org/povray.advanced-users/thread/%3Cweb.5845a06cc97737fcc437ac910%40news.povray.org%3E/
> 
> So modifying that so Pixel "size" is described in POV-units, then we could have
> 
> #macro Zoom (PixelSize)
> camera {
>   orthographic
>   location <0, 0, -PixelSize>
>   look_at  <0, 0, 0>
>   right (x*image_width )*PixelSize
>   up    (y*image_height)*PixelSize
>   }
> #end
> 
> 
> (I haven't entirely determined what the best camera-to-lookAt distance is to
> avoid some weird things happening)
> 
> 
> 
>


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