POV-Ray : Newsgroups : povray.binaries.animations : Rotating Earth with day & night Server Time: 16 Dec 2018 22:59:02 GMT
  Rotating Earth with day & night (Message 1 to 10 of 10)  
From: Bald Eagle
Subject: Rotating Earth with day & night
Date: 17 May 2017 11:35:03
Message: <web.591c352c2c1e2036c437ac910@news.povray.org>
I quickly cobbled this together last night after looking up the slope pattern,
and doing a few rudimentary experiments.

Aside from a few filename and copy/paste errors, it went pretty smoothly.

Just a proof-of-concept, so nothing amazing with regard to composition,
textures, finishes, video quality, etc.

(Planetary image maps from:   http://planetpixelemporium.com/planets.html)


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Attachments:
Download 'earthdaynight.avi.dat' (3923 KB)

From: Stephen
Subject: Re: Rotating Earth with day & night
Date: 17 May 2017 12:11:01
Message: <591c3dd5$1@news.povray.org>
On 5/17/2017 12:34 PM, Bald Eagle wrote:
> I quickly cobbled this together last night after looking up the slope pattern,
> and doing a few rudimentary experiments.
>
> Aside from a few filename and copy/paste errors, it went pretty smoothly.
>
> Just a proof-of-concept, so nothing amazing with regard to composition,
> textures, finishes, video quality, etc.
>
> (Planetary image maps from:   http://planetpixelemporium.com/planets.html)
>


Neat! I like the way that the terminator is not sharp. I hadn't thought 
of using the slope pattern.
It is hard to be sure with the viewpoint. But does the Earth not rotate 
the other way?

-- 

Regards
     Stephen


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From: Bald Eagle
Subject: Re: Rotating Earth with day & night
Date: 17 May 2017 13:25:00
Message: <web.591c4ef442619e18c437ac910@news.povray.org>
Stephen <mca### [at] aolcom> wrote:
> But does the Earth not rotate the other way?

https://www.youtube.com/watch?v=TjgsnWtBQm0


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From: Stephen
Subject: Re: Rotating Earth with day & night
Date: 17 May 2017 18:08:27
Message: <591c919b$1@news.povray.org>
On 5/17/2017 2:24 PM, Bald Eagle wrote:
> Stephen <mca### [at] aolcom> wrote:
>> But does the Earth not rotate the other way?
>
> https://www.youtube.com/watch?v=TjgsnWtBQm0
>
>


George Reeves was the only true Superman.

-- 

Regards
     Stephen


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From: Bald Eagle
Subject: Re: Rotating Earth with day & night
Date: 17 May 2017 18:25:01
Message: <web.591c950d42619e18c437ac910@news.povray.org>
Stephen <mca### [at] aolcom> wrote:

> George Reeves was the only true Superman.


Don't forget Keanu   ;)
https://www.youtube.com/watch?v=9DYJMfJn4go


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From: Stephen
Subject: Re: Rotating Earth with day & night
Date: 17 May 2017 18:51:43
Message: <591c9bbf$1@news.povray.org>
On 5/17/2017 7:23 PM, Bald Eagle wrote:
> Stephen <mca### [at] aolcom> wrote:
>
>> George Reeves was the only true Superman.
>
>
> Don't forget Keanu   ;)
> https://www.youtube.com/watch?v=9DYJMfJn4go
>
>
>
You seem to be more au fait with this cinematography fad than I am. :)


-- 

Regards
     Stephen


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From: omniverse
Subject: Re: Rotating Earth with day & night
Date: 17 May 2017 22:05:01
Message: <web.591cc76342619e189c5d6c810@news.povray.org>
Stephen <mca### [at] aolcom> wrote:
> On 5/17/2017 12:34 PM, Bald Eagle wrote:
> > I quickly cobbled this together last night after looking up the slope pattern,
> > and doing a few rudimentary experiments.
> >
> > Aside from a few filename and copy/paste errors, it went pretty smoothly.

I had to download the file and rename to get rid of the dat extension, then open
into WMP because Windows 10 refuses to play it directly. I don't give up easily.

> > Just a proof-of-concept, so nothing amazing with regard to composition,
> > textures, finishes, video quality, etc.
> >
> > (Planetary image maps from:   http://planetpixelemporium.com/planets.html)
> >
>
> Neat! I like the way that the terminator is not sharp. I hadn't thought
> of using the slope pattern.
> It is hard to be sure with the viewpoint. But does the Earth not rotate
> the other way?

Everything is moving opposite way. Moon orbiting Earth, Earth orbiting Sun, Sun.
All clockwise.
;)
Or in POV-Ray terms, depending on camera setup, rotate +y instead of -y.

What I'm wondering most of all is why the Sahara Desert in Africa is all lit up.
The other lights appear to be in their proper places, while north Africa looks
like a large metropolitan area.

Night and day terminator can be tricky to get right, as I know having tried it
myself.
Doesn't help that there's nothing real to compare to, since the Space Station
photos I've seen are either fully night time or a day/night terminator with no
artificial lighting visible at all in the darkness.

Bob


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From: Stephen
Subject: Re: Rotating Earth with day & night
Date: 18 May 2017 06:09:44
Message: <591d3aa8$1@news.povray.org>
On 5/17/2017 11:01 PM, omniverse wrote:
> What I'm wondering most of all is why the Sahara Desert in Africa is all lit up.
> The other lights appear to be in their proper places, while north Africa looks
> like a large metropolitan area.
>

It is the image map. I recognised it when I stepped through the frames.
The latest from Blue Marble has that detail.
I have picked up a few sets over the years and comparing it to one from 
2008. You can see the lights coming on all over Africa and South America.

The image map might have been processed to get rid of the blue 
background. Which might enhance the contrast.

> Night and day terminator can be tricky to get right, as I know having tried it
> myself.
> Doesn't help that there's nothing real to compare to, since the Space Station
> photos I've seen are either fully night time or a day/night terminator with no
> artificial lighting visible at all in the darkness.


You are right. RL can be so disappointing. :)

-- 

Regards
     Stephen


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From: Stephen
Subject: Re: Rotating Earth with day & night
Date: 18 May 2017 07:10:44
Message: <591d48f4$1@news.povray.org>
On 5/18/2017 7:09 AM, Stephen wrote:
> It is the image map. I recognised it when I stepped through the frames.

That is sad. That I recognised a particular image map shows my 
dedication. I started animating the Earth around 2008 and keep returning 
to it.
Using the slope map to blend the day and night maps is something I did 
not think of doing. I used CSG and layered spheres. It made for 
complicated mechanics. But that was the fun. :)

-- 

Regards
     Stephen


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From: Bald Eagle
Subject: Re: Rotating Earth with day & night
Date: 18 May 2017 11:40:01
Message: <web.591d876842619e18c437ac910@news.povray.org>
"omniverse" <omn### [at] charternet> wrote:
> Stephen <mca### [at] aolcom> wrote:

> Everything is moving opposite way. Moon orbiting Earth, Earth orbiting Sun, Sun.
> All clockwise.
> ;)
> Or in POV-Ray terms, depending on camera setup, rotate +y instead of -y.

I'm sure that's entirely my doing - too busy with the 9 planets and 27 moons and
the directive hierarchy and the macros and bounding boxes and other bits that
make up the ~1100 lines of code.
I'll look it all over on my next run through and check the signs.
The moon does rotate opposite to the Earth so that the same face is always
pointed toward Earth.   I suppose I ought to take a very close look at that and
figure out exactly _which_ face should be doing that.

> What I'm wondering most of all is why the Sahara Desert in Africa is all lit up.
> The other lights appear to be in their proper places, while north Africa looks
> like a large metropolitan area.


Yeah, that was one of the initial filename / copy-paste errors - I was using the
same image map for both day and night   :|   Then I fixed it and had to black
out the early color indices to get something that looked ok.

********************************************************************
Does anyone know if there's an automatic way in POV-Ray to get the number of
entries in the color index of the image map?
********************************************************************


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