I want to make an animation of a rotating earth, with some extra's:

Somewhere on the net I found high-res pictures of the earth "by day" and
"by night". My idea is to combine these pictures on one rotating sphere.

In my opinion, this is not a trivial task. Has someone experience with
this? How can I set this up?

Please send your answer and/or comments to my e-mail adress
jan### [at] wxsnl

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If I were to do this I would paste the two pictures together using picture
editing software.

Mike

"A. Jans-Beken" <jan### [at] wxsnl> wrote in message
news:38BF75C8.78D36056@wxs.nl...
> I want to make an animation of a rotating earth, with some extra's:
>
> Somewhere on the net I found high-res pictures of the earth "by day" and
> "by night". My idea is to combine these pictures on one rotating sphere.
>
> In my opinion, this is not a trivial task. Has someone experience with
> this? How can I set this up?
>
> Please send your answer and/or comments to my e-mail adress
> jan### [at] wxsnl
>

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You could use a gradient texture map. On one side of the sphere is one of
the image maps and on the other is the other image map. A small area between
then could fade from one to other.

-- 
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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"Nieminen Juha" <war### [at] sarakerttunencstutfi> wrote in message
news:38bfab17@news.povray.org...
|   You could use a gradient texture map. On one side of the sphere is one of
| the image maps and on the other is the other image map. A small area between
| then could fade from one to other.

I emailed this same thing as an easy way last night but having since tried it
out it doesn't appear to be a plausible way to go.  The other way I had said was
how I had actually done it before by using layered textures and two spheres.
The problem in the texture_map method is with the map_type needing to be
spherical and when placing the gradient texture_map of the two images onto the
sphere they no longer fit right.

Bob

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This is from my cyclopedia:
 Ron Parker provided this solution, which he derived from Chris Colefax:

  #macro DoubleImage ( front,back )
    radial
    pigment_map {
      [ .5 front ]
      [ .5 back rotate 180*y ]
    }
  #end

  #declare f=pigment { image_map{ sys "heads.bmp" once } translate -.5 }
  #declare b=pigment { image_map{ sys "tails.bmp" once } translate -.5 }

  #declare coin = cylinder {
    -.1*z,.1*z,1
    texture { pigment { color rgb 1 } }
    texture { pigment { DoubleImage(f,b) } }
    }

You will need to adjust the pigments, and getting them to rotate could be
tricky. I would think that the globe would rotate, and as the images move
across the terminus, it is displayed with the other image. Since that was a
bit glib, what I mean is that we see, say. New York at night, then as the
world turns we see it in the daytime map

Josh

"A. Jans-Beken" wrote:

> I want to make an animation of a rotating earth, with some extra's:
>
> Somewhere on the net I found high-res pictures of the earth "by day" and
> "by night". My idea is to combine these pictures on one rotating sphere.
>
> In my opinion, this is not a trivial task. Has someone experience with
> this? How can I set this up?
>
> Please send your answer and/or comments to my e-mail adress
> jan### [at] wxsnl

--

Josh English
eng### [at] spiritonecom
ICQ: 1946299
"Stress is when you wake up screaming and realize you haven't fallen asleep
yet."

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"A. Jans-Beken" wrote:
> 
> I want to make an animation of a rotating earth, with some extra's:
> 
> Somewhere on the net I found high-res pictures of the earth "by day" and
> "by night". My idea is to combine these pictures on one rotating sphere.
> 
> In my opinion, this is not a trivial task. Has someone experience with
> this? How can I set this up?

	I'd start by trying two clipped hemispheres, one with each map
and rotating them both the same amount.

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