|
 |
This may not help much, but here goes...
I wanted to do something similar but not for the Earth/Moon/Sun system.
It was for a science fiction story I was working on that takes place
on a planet that orbits a star 20 lightyears away. This is actually a
binary planet where two approximately equal mass planets orbit each
other (or around the center of mass of the two planets) and both orbit
the star. The two planets are tidally locked to each other. I wanted
to discover the dynamics of this world.
I wrote a simple model in POVRay and created an animation that captured
one frame per hour for one year (143 Earth days) and clearly showed the
geometry and timing of eclipses.
Notes:
- as was mentioned, you have to be careful about scale
- I didn't try modeling the elliptical nature of orbits - all orbits
are simple circles
- since I'm creating the world as a work of fiction, I have some room
to adjust the parameters to my suiting.
I can make this model available to you if you wish. It could be
adjusted to give an "impression" of the Earth/Moon system but couldn't
be used to give accurate predictions of eclipses, etc.
David Buck
gvdeynde wrote:
> Hi Mike,
>
> Thanks for the info. I've tried Celestia but thought it might be too
> complex for my son.
>
> Concerning PovRay: I have some experience already (I'm playing with it
> since version 2 or so, have modeled our house in it, did some artwork
> for some websites I made, etc). So I think I can come up with something,
> I was just wondering if somebody already did something close to this and
> I could work further based on that...
>
> I'll have a look at Geogebra...
>
> thanks again,
> gert
>
> On 2009-01-06 14:33, SharkD wrote:
>> You might want to try Celestia, a real-time planetarium program.
>> Certainly, you can do the same things in POV-Ray, but there are
>> several caveats:
>>
>> 1) POV-Ray is not a real-time program. You can't preview changes or
>> interact with the scene in real-time. The best you can do is render
>> individual frames to create a movie--which can be a time consuming
>> process, and you'll have to start the process over from the beginning
>> each time you make a mistake.
>> 2) POV-Ray can suffer from floating point/rounding errors when the
>> objects get too large and/or too distant.
>> 3) POV-Ray takes a long time to master, in general; and creating
>> scenes is usually a laborious process.
>>
>> You could also try GeoGebra, which is a real-time dynamic geometry
>> software. You could create representations of the planets as well as
>> the shadows they cast on other bodies using geometric objects. This
>> program is limited, however, to two dimensions.
>>
>> Hope that helps.
>>
>> -Mike
>>
>> gvdeynde wrote:
>>> Hello all,
>>>
>>> First of all, my best wishes to all of you. And to the developers of
>>> PovRay: keep up the good work; we're all grateful for the job you're
>>> doing.
>>>
>>> My 5-year old son is very interested and intrigued by the interplay
>>> of the sun/earth/moon and how this creates day, night, seasons, ...
>>> Also the mechanism of a solar and lunar eclipse (who is casting a
>>> shadown on who) has caught his attention.
>>>
>>> Since I lack a mechanical model of this three body system (I remember
>>> we had this in our geography classroom when I was in secondary
>>> school: you could turn a handle and then by means of gears the bodies
>>> would rotate and move), I was planning to do some animations with
>>> PovRay.
>>>
>>> I don't want to re-invent the wheel, hence my question: is there
>>> anybody here who has done something similar with PovRay? I would like
>>> to end up with a small number of input files (or a single one) for
>>> which the clock variable would both make the bodies rotate and move
>>> the camera to show the different aspects (night/day, eclipse,...). Do
>>> you know of a site or reference work where I could get approximate
>>> data (good enough for this purpose of an educational animation) for
>>> the astronomy data?
>>>
>>> Thanks for your tips!
>>>
>>> bye,
>>> gert
>>>
>>>
Post a reply to this message
|
|
