Somebody on one of the NASA sites was describing the surface of Europa
as probably looking like
"broken glass repaired by icy goo rising up from below". I took that
colorful comment as a POVray height_field challenge.

We're looking at Jupiter and IO from LAT: 77° 37.5' N, LONG: 2°  W and
+-3 miles above
the surface of Europa. The distances between the light source, and the
planets as well as
planet diameters are to scale: 1 pov unit=100 kilometers. Rendered
with POVray 3.1 

The shadows on Jupiter are cast by POVray, not painted on later. The
center shadow on Jupiter is the shadow of the moon we're standing on
(neato). It is night time from our viewing location but I imagine the
landscape would be pretty well lit by the light of a full Jupiter.
Ever been up to the Sierra Nevadas on a full moon lit night? It looks
like day time!

Thank you "SY" at news.povray.org for the following post...

"// Mean distance of the sun from Jupiter: 800E+6 km = 8000000E+2
units
// Sun's diameter is approx 1.4E6km = 1.4E4 = 14000 units
// use an area light to simulate the sun
light_source { <0,0,-8000000> color rgb <1,1,0.85> 
               area_light x*14000, y*14000,3,3 adaptive 1 jitter
               rotate y*-30 }
//light_source { <5000000,0,-8000000> color rgb <1,1,0.85>  }

The altitude of the camera above the surface of Europa is not to
scale.

The "Milky Way" is bozo colormap pattern mapped onto a cube.

The starfield was created with Starry Night Backyard and Universe.

The night sky is fairly close to being astronomically correct for the
above 
location on 01/03/2003 at approx. 18:50 UT (According to Starry Night
Backyard by SPACE.com)

Jupiter system data based on "JupSat 95 v.1.14 by
Gary Nugent
54a Landscape Park 
Churchtown
Dublin 14
Ireland
http://indigo.ie/~gnugent/dnso/
gnu### [at] indigoie

Jupiter, IO, and Europa data courtesy NASA's "Welcome to the Planets"
http://jpl.nasa.gov

Location on Europa, date, time based on "Starry Night Backyard" by
SPACE.com

Enjoy!
--Blane Bizzaro

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Attachments:
Download 'on_europa.jpg' (336 KB)

Preview of image 'on_europa.jpg'

Nice pic, but the jagged look on the near vertical edges of your
height-field really distract. Consider using a higher resolution
height-field or using the new height-field macros to improve this.

 -Shay

Blane Bizzaro <bla### [at] bizzarocreationscom> wrote in message
news:3cb### [at] mailpovrayorg...

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That was bothering me to. Think you could share an example of a macro
that would fix that and how to implement it in the scene?

Thanks.
--Blane
On Wed, 17 Apr 2002 16:28:19 -0500, "Shay" <sah### [at] simcopartscom> wrote:

>Nice pic, but the jagged look on the near vertical edges of your
>height-field really distract. Consider using a higher resolution
>height-field or using the new height-field macros to improve this.
>
> -Shay
>
>Blane Bizzaro <bla### [at] bizzarocreationscom> wrote in message
>news:3cb### [at] mailpovrayorg...
>
>

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(From the 'everything I need to know about astronomy, I learned
from popular media' section...)

"Regardless of viewing location, the great red spot is ALWAYS
visible when looking at Jupiter."
-- 
Tim Cook
http://empyrean.scifi-fantasy.com

-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GFA dpu- s: a?-- C++(++++) U P? L E--- W++(+++)>$
N++ o? K- w(+) O? M-(--) V? PS+(+++) PE(--) Y(--)
PGP-(--) t* 5++>+++++ X+ R* tv+ b++(+++) DI
D++(---) G(++) e*>++ h+ !r--- !y--
------END GEEK CODE BLOCK------

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"Timothy R. Cook" <tim### [at] scifi-fantasycom> a écrit dans le message de
news: 3CBE32ED.E154EA6E@scifi-fantasy.com...
>
> "Regardless of viewing location, the great red spot is ALWAYS
> visible when looking at Jupiter."
> --
LOL, how do you explain that strange behaviour?
When it's facing oposite side it's invisible indeed.
Jupiter's mass isn't huge enough to wrap space frame that way.
Marc

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> Thank you "SY" at news.povray.org for the following post...
>
> "// Mean distance of the sun from Jupiter: 800E+6 km = 8000000E+2
> units
> // Sun's diameter is approx 1.4E6km = 1.4E4 = 14000 units
> // use an area light to simulate the sun
> light_source { <0,0,-8000000> color rgb <1,1,0.85>
>                area_light x*14000, y*14000,3,3 adaptive 1 jitter
>                rotate y*-30 }
> file://light_source { <5000000,0,-8000000> color rgb <1,1,0.85>  }

You are welcome.
If you need some more data, please let me know...

regards
SY

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Very nice scene.

One remark: (beside the HF artefacts) the lighting is IMO inconsistent.
Jupiter is lit from sun "behind" the camera. But looking on the small knob
of europa's surface to the lower left it seems to be lit from Jupiter which
is in FRONT of the cam. Although Jupiter IS bright, the major lighting
should come from the sun.

Jupiter is a picture. What about placing the texture-only jupiter of the the
"jupiter" post in p.b.s-f ? Then you could animate each colour band on it's
own...

good job
regards
SY

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> > "Regardless of viewing location, the great red spot is ALWAYS
> > visible when looking at Jupiter."
> > --
> LOL, how do you explain that strange behaviour?
> When it's facing oposite side it's invisible indeed.
> Jupiter's mass isn't huge enough to wrap space frame that way.
> Marc

due to Jupiter's rotation it is only a matter of time *gg*
regards
SY

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I haven't tried them myself, but I think that the heightfield macros in 3.5
will return a better result than the height_field command. I'm not sure
where they are located, but you could use the search function to find them
in the docs.

 -Shay

Blane Bizzaro <bla### [at] bizzarocreationscom> wrote in message
news:3cbd57ab.334778495@news.povray.org...

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The higher res tip was a good one Shay. The first height field image
was only 600x600px by 8 bit. This new one is 2000x2000 by 24 bit.
Thanks!

--Blane

On Wed, 17 Apr 2002 16:28:19 -0500, "Shay" <sah### [at] simcopartscom> wrote:

>Nice pic, but the jagged look on the near vertical edges of your
>height-field really distract. Consider using a higher resolution
>height-field or using the new height-field macros to improve this.
>
> -Shay
>
>Blane Bizzaro <bla### [at] bizzarocreationscom> wrote in message
>news:3cb### [at] mailpovrayorg...
>
>

Post a reply to this message

On Wed, 17 Apr 2002 16:28:19 -0500, "Shay" <sah### [at] simcopartscom> wrote:

>Nice pic, but the jagged look on the near vertical edges of your
>height-field really distract. Consider using a higher resolution
>height-field or using the new height-field macros to improve this.
>
> -Shay
>
>Blane Bizzaro <bla### [at] bizzarocreationscom> wrote in message
>news:3cb### [at] mailpovrayorg...
>
>

Post a reply to this message

The higher res idea worked out pretty good. Thanks for the tip!
--Blane

Shay <sah### [at] simcopartscom> wrote in message
news:3cbec869$1@news.povray.org...
> I haven't tried them myself, but I think that the heightfield macros in
3.5
> will return a better result than the height_field command. I'm not sure
> where they are located, but you could use the search function to find them
> in the docs.
>
>  -Shay
>
> Blane Bizzaro <bla### [at] bizzarocreationscom> wrote in message
> news:3cbd57ab.334778495@news.povray.org...
>
>

Post a reply to this message

Attachments:
Download 'on_europa2.JPG' (102 KB)

Preview of image 'on_europa2.JPG'

"Blane Bizzaro" <bla### [at] bizzarocreationscom> wrote in
news:3cc05a71@news.povray.org: 

> The higher res idea worked out pretty good. Thanks for the tip!

I think the lighting is still a little wacky.  You might want to try going 
down to one light to the extreme left or right of the scene components 
(well off the screen) and using radiosity to backfill the shadows.

The contrast with the starfield is also way too low; the stars and plane of 
the galaxy should be much dimmer.

I would be interested in seeing the source, BTW.

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