Ahhh, linux.... something I'm not running on my computers here. Guess I'll
pass then, thanks anyhow for the offer!
-- 
Bob H.
http://www.3digitaleyes.com

"Wolfgang Wieser" <wwi### [at] gmxde> wrote in message
news:401cd9fc@news.povray.org...
> >
> You will need libz, libpng, libbz2 (on any recent linux distro),
> hlib (on my homepage) and Qt-3.x (only free for linux).
> Then, I could send you hlib-compression-addon, QTXlib and my conversion
> utility. Compile all that using gcc-3.x on a linux box and there you go.
> (The conversion utility has graphical output. When editing the source,
> you may come along without Qt and QTXlib.)
>
> In case anybody (possibly you) is interested in that I may make it
> available on my home page in a week or so (there is an exam this
> week...).

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Among other things, Hughes, B. wrote:

> I don't know of any water having green colorations without
> plantlife within it so its natural to think of it as life-bearing.

Copper and iron salts can be green too 
(<http://www.wqa.org/sitelogic.cfm?ID=346>).

-- 
light_source{9+9*x,1}camera{orthographic look_at(1-y)/4angle 30location
9/4-z*4}light_source{-9*z,1}union{box{.9-z.1+x clipped_by{plane{2+y-4*x
0}}}box{z-y-.1.1+z}box{-.1.1+x}box{.1z-.1}pigment{rgb<.8.2,1>}}//Jellby

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Oh in water, life should be easier to born than on land ( less cosmic rays,
more even temperature, no need of  rain, no gravity to overcome, ect...) ,
so life could exist in seas hundreds millions years before on dry land.
Marc


401d7942$1@news.povray.org...
> "Marc Jacquier" <jac### [at] wanadoofr> wrote in message
> news:401cc9d3$1@news.povray.org...
> >

> > 401c9259$1@news.povray.org...
> > > Of course, one thing a planet with water needs is plantlife
> >
> > It should have no chance to do so in the time liquid water was at the
> > surface of mars.
>
> Always debateable but, yes, I think you have a good point there. I used
the
> word plantlife in a very broad sense, including things like algae and even
> protist slimey stuff someplace. :-)
>
> This brings up something about the coloration of the water used here in
> Wolfgang's rendering. My first thought was of water-borne life because of
> the greenish tinge. A large manmade lake nearby here has a sometimes vivid
> green coloring in certain places, brownish in others, yet overall tends to
> be green hues. I don't know of any water having green colorations without
> plantlife within it so its natural to think of it as life-bearing.
>
> That might be something to change then to reflect a more sterile water on
an
> early Mars.
>
> Bob H.
>
>

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"Jellby" <jel### [at] M-yahoocom> wrote in message
news:401d8698@news.povray.org...
>
> Copper and iron salts can be green too
> (<http://www.wqa.org/sitelogic.cfm?ID=346>).

Glad you showed that. I wasn't considering inorganic colorations.

I also think of the bacteria at Yellowstone National Park, in the hotsprings
there. Colorful stuff and not "plantlife" either. I keep using that word too
generally and used it again to mean any kind of microorganism.

Here's an article concerning Jupiter's moon Europa, about possibility of
bacteria and the colors on it's surface:
http://nai.arc.nasa.gov/news_stories/news_detail.cfm?ID=53

Bob H.

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[following the nice discussion about signs of life...]

Actually, the coloring of the water was the major problem. 

I'm not sure if an ocean on Mars would be so blue; at least 
there is no blue sky which could be reflected. 
And then I had to make it much darker than I thought because 
if I leave the water more transparent it no longer looks like 
liquid water at all but like dark dry sediments. Or maybe, this 
perception varies quite a lot between different people. 

And yes, I decided to make the water (absorption) a bit greenish 
because it turned out that I liked it...
But now, I will be telling people it's some anorganic salts ;)
(Thanks Jellby)

BTW, there is now an updated version on my homepage. I removed 
some spurious water in the background by re-adjusting the level. 
Especially have a look at the crater right back!

http://www.cip.physik.uni-muenchen.de/~wwieser/render/img/mars/3craters-ese-2-1200.jpg

Wolfgang

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Looks better.

There are some peculiar squiggles running from lower right toward the
middle, and comparing this new render to the other I see it was also visible
there. Just much clearer to see now. Perhaps a isosurface with too low a
max_gradient?

Bob H.

"Wolfgang Wieser" <wwi### [at] gmxde> wrote in message
news:401ea555@news.povray.org...
---snip---
>
http://www.cip.physik.uni-muenchen.de/~wwieser/render/img/mars/3craters-ese-2-1200.jpg

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High!

Wolfgang Wieser schrieb:

  I'm not sure if an ocean on Mars would be so blue; at least
  there is no blue sky which could be reflected.

I don't think so... as long Mars was able to maintain liquid water on its surface, the
atmosphere must have been much denser
then today, and so the sky also was coloured up to the zenith, unlike nowadays. And
even
today sometimes, depending on
weather and dust saturation of the air, the reddish/yellowish horizon seam turns
bluish -
so also the early Martian oceans
would probably have been deep blue like Earth's oceans as seen from orbit

  BTW, there is now an updated version on my homepage. I removed
  some spurious water in the background by re-adjusting the level.
  Especially have a look at the crater right back!

Did you use 8 or 16bit resolution for the heightfield? I assume that you used
Christoph's
IC_HF_Sphere function to wrap it
around the sphere... perhaps in the future, we might be able to reduce rendering time
by
just rendering those portions (tiles)
of the heightfield which would be actually visible in the image; currently, I try to
modify IC_HF_Sphere to render only
sections of a spherical heightfield...

See you in Khyberspace - http://home.arcor.de/yadgar/khyberspace/index-e.html
Afghanistan Chronicle: http://home.arcor.de/yadgar/index-e.htm
Home-made electronic music: http://home.arcor.de/yadgar/music/

Yadgar ((:->

Now playing: Upstairs in my House (Men at Work)

--
Pashto 2.0, a protocol language for the Advanced Fractal Geometric Heightfield and
Navigation Implementation-Sensitive
Texture Analysis Network

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>   BTW, there is now an updated version on my homepage. I removed
>   some spurious water in the background by re-adjusting the level.
>   Especially have a look at the crater right back!
> 
> Did you use 8 or 16bit resolution for the heightfield? 
>
16 bit. But no height field. 

Wolfgang

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Hughes, B. wrote:
> There are some peculiar squiggles running from lower right toward the
> middle, and comparing this new render to the other I see it was also
> visible there. Just much clearer to see now. Perhaps a isosurface with too
> low a max_gradient?
> 
I see what you mean. 
There are more spots of this sort. 
They are not related to the water surface because they are also 
visible on the rendering without water. 

I'm not sure what it is but I doubt it is due to max_gradient (which 
was set too high and hence the reason for the render to take soo long). 
I'll see if changing accuracy/gradient will help. 

OTOH, it does not really hurt, IMO. 

Wolfgang

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High!

Wolfgang Wieser schrieb:

  16 bit. But no height field.

So it must be a mesh - how long did it take to parse?

See you in Khyberspace!

Yadgar

Now playing: Fashion Fever (Level 42)

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