Renderdog wrote:
> 
> Wow, those are impressive images! I've never seen an image such as your
> Himalaya image, where you can see the curvature of the earth and the
> non-smoothness of the surface (mountains). It would make a great backdrop
> for an animation. I like the atmosphere also.

Thanks.

> How was the earth's surface modeled, as a triangle mesh or some other
> method?

A mesh would have taken way too much memory.  Remember the whole earth
with 1km resolution in a regular lat/lon mesh would mean about 1.8 billion
triangles.  A 45x45 degree tile still has 29 million vertices which (with
normal vectors) would use about 700 Mb (not counting the face and normal
indices!)

I used an isosurface with an image_map pigment function defining the
height of the terrain.  This only uses 2 byte per pixel and nothing more
(about 56 Mb per tile for the height data). 

> Another way to show the depths of the seas would be to color-code a smooth
> surface (deeper waters darker blue).

I have also made test with color depending on the height and without the
image_map texture.  Will see if i can post some sample for that too.

> How long did it take to render? I've always been impressed with how fast
> POV-Ray can render huge files.

The whole image at 6400x4800 took about 1-2 days.  The speed of rendering
an isosurface does not much depend on the detail level (although more
detailed data of course requires higher max_gradient).  

Christoph

-- 
POV-Ray tutorials, include files, Sim-POV,
HCR-Edit and more: http://www.tu-bs.de/~y0013390/
Last updated 28 Feb. 2003 _____./\/^>_*_<^\/\.______

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Hugo Asm wrote:
> 
> Where are the icey northpole?
> Not to mention, the southpole?
> 

The south pole is not visible. :-)  There is data for the polar ice cover
but i did not try to add it yet.

Christoph

-- 
POV-Ray tutorials, include files, Sim-POV,
HCR-Edit and more: http://www.tu-bs.de/~y0013390/
Last updated 28 Feb. 2003 _____./\/^>_*_<^\/\.______

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Hi!

this is ages after you posted this, but i was wondering if i could use your
picture of the earth and use it for my own personal use?

Thanks a lot!!!















Christoph Hormann <chr### [at] gmxde> wrote:
> At the first glance this probably looks like yet another boring earth
> image but it is somewhat different.
>
> I used the 1km resolution data sets for geometry and coloring available
> on:
>
> http://earthobservatory.nasa.gov/Newsroom/BlueMarble/
>
> and used real surface geometry instead of bump mapping.  Of course the
> detail is hardly visible at this size, the second image shows a sample
> from the original render at 6400x4800 pixel size.
>
> It was of course not possible to render the whole planet in one piece, the
> height data alone is about 2GB.  Therefore i split it into 45x45 degree
> tiles and rendered them one after the other (with some overlap).
>
> Files with cloud coverage data are available at the mentioned site too but
> with strongly varying quality.  A short distance view with clouds of parts
> of europe (with 2.5x exaggerated height) can be seen on:
>
> http://www.schunter.etc.tu-bs.de/~chris/files/earth_a2.jpg
>
> the same without clouds on:
>
> http://www.schunter.etc.tu-bs.de/~chris/files/earth_a1.jpg
>
> I searched a lot for cloud height data which would be important for
> realistic clouds but i could not find anything useful.
>
> I also made a view with natural height scale of western himalayas and
> karakorum:
>
> http://www.schunter.etc.tu-bs.de/~chris/files/earth_a3l.jpg
>
> this shows the available detail level in the data and also the varying
> quality in some parts (note the broad band of lower quality on the right).
>
> Christoph
>
> --
> POV-Ray tutorials, include files, Sim-POV,
> HCR-Edit and more: http://www.tu-bs.de/~y0013390/
> Last updated 28 Feb. 2003 _____.//^>_*_<^/.______

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See the following:

http://www.wikipov.org/ow.asp?EarthModel


Neil

"cedriccrucke" <ced### [at] hotmailcom> wrote in message 
news:web.41fa53c2bf3d391c20b6508a0@news.povray.org...
> Hi!
>
> this is ages after you posted this, but i was wondering if i could use 
> your
> picture of the earth and use it for my own personal use?
>
> Thanks a lot!!!
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> Christoph Hormann <chr### [at] gmxde> wrote:
>> At the first glance this probably looks like yet another boring earth
>> image but it is somewhat different.
>>
>> I used the 1km resolution data sets for geometry and coloring available
>> on:
>>
>> http://earthobservatory.nasa.gov/Newsroom/BlueMarble/
>>
>> and used real surface geometry instead of bump mapping.  Of course the
>> detail is hardly visible at this size, the second image shows a sample
>> from the original render at 6400x4800 pixel size.
>>
>> It was of course not possible to render the whole planet in one piece, 
>> the
>> height data alone is about 2GB.  Therefore i split it into 45x45 degree
>> tiles and rendered them one after the other (with some overlap).
>>
>> Files with cloud coverage data are available at the mentioned site too 
>> but
>> with strongly varying quality.  A short distance view with clouds of 
>> parts
>> of europe (with 2.5x exaggerated height) can be seen on:
>>
>> http://www.schunter.etc.tu-bs.de/~chris/files/earth_a2.jpg
>>
>> the same without clouds on:
>>
>> http://www.schunter.etc.tu-bs.de/~chris/files/earth_a1.jpg
>>
>> I searched a lot for cloud height data which would be important for
>> realistic clouds but i could not find anything useful.
>>
>> I also made a view with natural height scale of western himalayas and
>> karakorum:
>>
>> http://www.schunter.etc.tu-bs.de/~chris/files/earth_a3l.jpg
>>
>> this shows the available detail level in the data and also the varying
>> quality in some parts (note the broad band of lower quality on the 
>> right).
>>
>> Christoph
>>
>> --
>> POV-Ray tutorials, include files, Sim-POV,
>> HCR-Edit and more: http://www.tu-bs.de/~y0013390/
>> Last updated 28 Feb. 2003 _____.//^>_*_<^/.______
>
>
>

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