High!

I implemented Thomas de Groot's suggestion for my Saturnian system model 
(and will do this in the future also for the other planets, which also 
all have some axial tilt) and started with rendering two views of Pan, 
the innermost regular moon of Saturn (except for some 150 tiny 
"moonlets" orbiting still more inward), from 5,000 and from 100 kms.

To get the camera centered on Pan, I had to rotate its location and 
look_at vectors according to Saturn's axial orientation using vrotate():

     #declare Final_Pos_Pan = Pos_Saturn + vrotate(Pos_Pan, 
<bodies[3][4]-(90-bodies[72][10]), 90-bodies[72][11], 0>);
     #declare camPos = Final_Pos_Pan + 100 * <sin(radians(39)), 0, 
cos(radians(39))>;
     #declare camLook = Final_Pos_Pan;

Note that the camera still looks towards Pan from the ecliptic plane, 
which is identical with the x-z plane; later on, I will use the 
respective planet's (or moon's, in case of axially tilted moons like our 
own Moon) equatorial plane as reference for camera positioning.

When zooming close to Pan, I had to divide the global scaling factor 
(normally 13347) by 100, otherwise it would have been rendered incompletely.

A real flaw is that Pan doesn't orbit within the Encke gap (see 
http://en.wikipedia.org/wiki/Pan_(moon) ); I assume that this is caused 

(or, as well, inaccuracies in building multipartite texture_maps from 
them). Perhaps, in the more distant future, I'll replace this simple 
"monolithic" ring by thousands of individual ring objects, thus allowing 
individual thicknesses, corrugations and dynamic clump and tidal wave 
structures.

Also for now, the moons are simple spheroids rather than realistic 
asteroidal/small planet bodies with a real surface relief; for most of 
Saturn's (and the other planets') small moons, the surface structures 
would be entirely or mostly fictitious, with only vague hints at shapes 
gleaned from Voyager, Galileo and Cassini probe photos.

See you in Khyberspace!

Yadgar

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Attachments:
Download '2009-12-04 pan, take 1.jpg' (22 KB) Download '2009-12-04 pan, take 2.jpg' (11 KB)

Preview of image '2009-12-04 pan, take 1.jpg'

Preview of image '2009-12-04 pan, take 2.jpg'

> High!
> 
> I implemented Thomas de Groot's suggestion for my Saturnian system model 
> (and will do this in the future also for the other planets, which also 
> all have some axial tilt) and started with rendering two views of Pan, 
> the innermost regular moon of Saturn (except for some 150 tiny 
> "moonlets" orbiting still more inward), from 5,000 and from 100 kms.
> 
> To get the camera centered on Pan, I had to rotate its location and 
> look_at vectors according to Saturn's axial orientation using vrotate():
> 
>     #declare Final_Pos_Pan = Pos_Saturn + vrotate(Pos_Pan, 
> <bodies[3][4]-(90-bodies[72][10]), 90-bodies[72][11], 0>);
>     #declare camPos = Final_Pos_Pan + 100 * <sin(radians(39)), 0, 
> cos(radians(39))>;
>     #declare camLook = Final_Pos_Pan;
> 
> Note that the camera still looks towards Pan from the ecliptic plane, 
> which is identical with the x-z plane; later on, I will use the 
> respective planet's (or moon's, in case of axially tilted moons like our 
> own Moon) equatorial plane as reference for camera positioning.
> 
> When zooming close to Pan, I had to divide the global scaling factor 
> (normally 13347) by 100, otherwise it would have been rendered 
> incompletely.
> 
> A real flaw is that Pan doesn't orbit within the Encke gap (see 
> http://en.wikipedia.org/wiki/Pan_(moon) ); I assume that this is caused 

> (or, as well, inaccuracies in building multipartite texture_maps from 
> them). Perhaps, in the more distant future, I'll replace this simple 
> "monolithic" ring by thousands of individual ring objects, thus allowing 
> individual thicknesses, corrugations and dynamic clump and tidal wave 
> structures.
> 
> Also for now, the moons are simple spheroids rather than realistic 
> asteroidal/small planet bodies with a real surface relief; for most of 
> Saturn's (and the other planets') small moons, the surface structures 
> would be entirely or mostly fictitious, with only vague hints at shapes 
> gleaned from Voyager, Galileo and Cassini probe photos.
> 
> See you in Khyberspace!
> 
> Yadgar
> 
> ------------------------------------------------------------------------
> 
> 
> ------------------------------------------------------------------------
> 
You have acuracy problems. That's why it got chopped like that.
You need more bits of precision than the 64 (80 internal) offered by the 
FPU.


Alain

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> When zooming close to Pan, I had to divide the global scaling factor 
> (normally 13347) by 100, otherwise it would have been rendered 
> incompletely.

...oops! Attached here is the correct image! With a slightly different 
angle position of the moon, 133.47 did not work anymore, it had to be 
198! Yes, modeling the Solar System goes to the limits of POV-Ray...

See you in Khyberspace!

Yadgar

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Attachments:
Download '2009-12-04 pan, take 4.jpg' (13 KB)

Preview of image '2009-12-04 pan, take 4.jpg'