On Sun, 23 Jan 2000 23:19:53 -0500, Andrea Ryan <ary### [at] global2000net>
wrote:

>What if the orbit is tilted?  The orbit of the Moon is tilted about 5.145
>degrees.  Would that be incorporated if the Moon is rotated on its axis, tilted
>over a little, translated, rotated 5.145 degrees and revolved around the
>Earth?  What if a elliptical orbit is desired?
>Brendan Ryan
>
>dcc wrote:

object
{
  Moon
  rotate <5.145,-360*y*clock,0>
  translate R*<cos(2*pi*clock), 0, E*sin(2*pi*clock)>
  // R is the major radius
  // E is the "Eggness", i.e. minor to major radius ratio
}


Peter Popov
pet### [at] usanet
ICQ: 15002700

Post a reply to this message

"Peter Popov" <pet### [at] usanet> wrote in message
news:Dt6LOK5zhY9yVXasthw9DVIrEWwn@4ax.com...
| On Sun, 23 Jan 2000 23:19:53 -0500, Andrea Ryan <ary### [at] global2000net>
| wrote:
|
| >What if the orbit is tilted?  The orbit of the Moon is tilted about 5.145
| >degrees.  Would that be incorporated if the Moon is rotated on its axis,
tilted
| >over a little, translated, rotated 5.145 degrees and revolved around the
| >Earth?  What if a elliptical orbit is desired?
| >Brendan Ryan
| >
|
| object
| {
|   Moon
|   rotate <5.145,-360*y*clock,0>
|   translate R*<cos(2*pi*clock), 0, E*sin(2*pi*clock)>
|   // R is the major radius
|   // E is the "Eggness", i.e. minor to major radius ratio
| }
|

No, wrong.  You have the axial tilt of the Moon before the rotation on it's
axis.  This would have it wobbling (it does anyhow though, about 6 degrees? not
sure of that).  The 'translate' instead of a 'rotate' for it's orbit is a good
idea... except....
You will need the 5 degree inclination after the ellipse is done.

Bob

Post a reply to this message

On Mon, 24 Jan 2000 11:35:01 -0600, "Bob Hughes"
<omn### [at] hotmailcom?subject=PoV-News:> wrote:

>No, wrong.  You have the axial tilt of the Moon before the rotation on it's
>axis.  This would have it wobbling (it does anyhow though, about 6 degrees? not
>sure of that).  The 'translate' instead of a 'rotate' for it's orbit is a good
>idea... except....
>You will need the 5 degree inclination after the ellipse is done.
>
>Bob

Ditto. It was just a quick demo anyway.


Peter Popov
pet### [at] usanet
ICQ: 15002700

Post a reply to this message

Thanks for help with the eccentricity of the orbit.
Brendan Ryan

Andrea Ryan wrote:

> What if the orbit is tilted?  The orbit of the Moon is tilted about 5.145
> degrees.  Would that be incorporated if the Moon is rotated on its axis, tilted
> over a little, translated, rotated 5.145 degrees and revolved around the
> Earth?  What if a elliptical orbit is desired?
> Brendan Ryan
>
> dcc wrote:
>
> > I've managed to make animation of a rotating sphere. What I really want to
> > do is rotate a sphere on it's axis while it orbits another rotating sphere.
> > Generally I export the scene out of Moray and animate in POV-ray, if that
> > makes a difference.
> >
> > I am hopeful someone can post an example of what the code would look like
> > for such a scene.
> >
> > Thanks
> >
> > dan

Post a reply to this message

Like Ken says, you need help Bob.

There's a really narrow line that you can cross, one day it all 
seems logical and straight forward, it just makes life a little
bit easier and more bearable, and before you know it you just 
can't live without it, that hash sign and the word "declare" are
rearing their ugly heads everywhere you look. 

Next day you'll have to rewrite the grocery bill with
declare statements before you can tell whether it's correct or 
not, but hopefully you'll be saved before it gets that bad. 

All hope is not lost, you didn't declare all of the values
for the camera, so hang in there Bob. 

-- 
Cheers
Steve              email mailto:sjl### [at] ndirectcouk

%HAV-A-NICEDAY Error not enough coffee  0 pps. 

web http://www.ndirect.co.uk/~sjlen/

or  http://start.at/zero-pps

  3:19am  up 3 days, 11:30,  6 users,  load average: 4.22, 4.09, 4.01

Post a reply to this message