Celestia Forums

Does exist an option or an other easy solution to enlarge planets (or other selected objects like astronefs) that we can see all systems and their planets otherwise than with their labels even if it's not so realistic anymore?
Indeed, I think it's quite more understandable to discover a system of planets like that because despite distances are not exact, you can still have an idea of the gaps between two planets and in the same time you can compare texture, size and shape of the planets. It's a quicker solution to see extrasolar system also!

Is is possible with Celestia ?

Imy wrote:Does exist an option or an other easy solution to enlarge planets (or other selected objects like astronefs) that we can see all systems and their planets otherwise than with their labels even if it's not so realistic anymore?
Indeed, I think it's quite more understandable to discover a system of planets like that because despite distances are not exact, you can still have an idea of the gaps between two planets and in the same time you can compare texture, size and shape of the planets. It's a quicker solution to see extrasolar system also!

Is is possible with Celestia ?

Imy,

If you have Celestia 1.5pre4 installed on your system, the magnification feature included in the Lua Edu Tools is certainly what you are looking for:
http://celestiaproject.net/forum/viewtopic.php ... &start=221

Another possibility is to make your own addon and create a new solar system with magnified objects.

I remember Andrea made an Orrery... don't know if it's still available.

bh wrote:I remember Andrea made an Orrery... don't know if it's still available.

bh has a very good memory, indeed.
My "Orrery" cel script is here (it was created for Celestia 1.4.1, dunno if it can work in 1.5pre4):
http://www.celestiamotherlode.net/creat ... nglish.zip
Practically it shows the Solar System with smaller planets scaled up, and bigger planets scaled down, together with a very very small star in the center.
This to show all planets altogether, without losing the Solar System dynamics and behaviour.
Hope this may help someway, but if you give a look at the solarsys you'll see immediately the way I used to obtain that.
Bye

Andrea

Thanks a lot Vincent : your tools are greats and must be integrate in basic package quickly!
I've followed Celestia development for some years and I don't know your job. I feel your tool is a great step for Celestia, more than technological stuffs : it's a real reason to continue to use Celestia, to use this program.

The magnification is particulary what I'm expecting for Celestia. But, If I can say that, it's a good beginning but it's limited to solar system and for planets : i've tried in 51 peg solar system and nothing have seemed to appear ; I haven't managed to focus on astero??d belt after Mars orbit, and i have looked for enlarging only hubble and earth but nothing. I hope this could be future way of development of your magnification algorithm !

I'm sorry Andrea, i didn't manage to download your zip from your link!

Imy wrote: I'm sorry Andrea, i didn't manage to download your zip from your link!

Don't worry, you are welcome.
Bye

Andrea

Imy wrote:The magnification is particulary what I'm expecting for Celestia. But, If I can say that, it's a good beginning but it's limited to solar system and for planets : i've tried in 51 peg solar system and nothing have seemed to appear ;

I've been thinking about extending the magnification option to all solar systems. Then, what behaviour would you expect when changing solar system (= new selection) with magnification enabled:
1- Automatically disable magnification in the previous solar system, and wait for user to check the box before enabling the magnification in the new solar system.
2- Automatically disable magnification in the previous solar system, and automatically enable magnification in the new selected solar system.
3- Enable magnification in all Solar systems once the magnification box is checked.

I would personnaly vote for 2. What about you ? Do you have other suggestions ?

Imy wrote:I haven't managed to focus on astero??d belt after Mars orbit, and i have looked for enlarging only hubble and earth but nothing. I hope this could be future way of development of your magnification algorithm !

The magnification option is already available for asteroids. You can define the type of object to magnify, along with the magnification coefficient, in the config.lua file:

----------------------------------------------------------------------------------------
-- Define objects to magnify when the magnification box is checked.
-- Objects to magnify can be:
-- "planets": magnify all the planets in our solar system;
-- "moons": magnify all the moons in our solar system;
-- "asteroids": magnify all the asteroids in our solar system;
-- "comets": magnify all the comets in our solar system;
-- "earth_moon": magnify the Earth and the Moon.
----------------------------------------------------------------------------------------

magnified_objects = "planets"

----------------------------------------------------------------------------------------

-- Define the different magnification coefficients.
----------------------------------------------------------------------------------------
planets_magnification = 2000
moons_magnification = 100
asteroids_magnification = 200000
comets_magnification = 2000
earth_moon_magnification = 30

As for spacecraft, I've removed this option because they are very different in size, and this was causing a mess in the display. Though, we could give the possibility to magnify specific objects from the body class (planet, moon, asteroid, comet, spacecraft). These bodies could be defined using a table in the config file:

magnified_object = {"Sol/Earth", "Sol/Earth/Hubble"}
object_magnification = {2000, 1e5}

Would you be OK with this ?

[EDIT]
Actually, you won't be able to magnify Hubble and Earth at the same time since magnified Earth will engulf Hubble. The magnification option doesn't modify SemiMajorAxis, but only Radius.

HI Vincent,

I think option 2 would be the right thing to use.

Just my 2 cents,

Guckytos

I've been thinking about extending the magnification option to all solar systems. Then, what behaviour would you expect when changing solar system (= new selection) with magnification enabled:
1- Automatically disable magnification in the previous solar system, and wait for user to check the box before enabling the magnification in the new solar system.
2- Automatically disable magnification in the previous solar system, and automatically enable magnification in the new selected solar system.
3- Enable magnification in all Solar systems once the magnification box is checked.

I would personnaly vote for 2. What about you ? Do you have other suggestions ?

I also think the second solution is the better because the probability that you have two closer solar systems to compare is low (maybe only in severals views?).

The magnification option is already available for asteroids. You can define the type of object to magnify, along with the magnification coefficient, in the config.lua file:

Well it's quite not very easy, isn't it ?!

Actually, you won't be able to magnify Hubble and Earth at the same time since magnified Earth will engulf Hubble. The magnification option doesn't modify SemiMajorAxis, but only Radius.

I think fundamentaly there is a problem with magnification.. I'm beginning to understand. When I want to see moon after enlarging planet, well it is black and inside earth. This is the same problem as suggested with hubble. I think (quickly) that magnification demand to select system : for hubble the system is only earth and moon and then you can change final distance between them, no?

I wonder what does magnification : this algorithm has to be trigged just before that object is shown : it doesn't modify any parameters of object, do it? That's to say eclipses are still exact, distances information and other parameters are still exact in the left top corner...

One reason for using enlarging object is to compare relative position of a point in a surface with another one which is on a reference object.
I'm wondering if in standard view, using arrows or vectors or bases would not be interesting to show, for instance, the rotation of planets on themselves Does exist a script for that?

I would suggest option #3.

or, maybe #4: provide "enable/disable magnification for the currently selected system" -- only changing the magnification for a system when mag/demag is explicitly changed while that system is selected.

As Imy points out, Celestia allows you to view multiple window panes. It'd be useful to be able to compare several different planetary systems using the same magnification factor in several different panes at the same time.

Guckytos wrote:I think option 2 would be the right thing to use.

Just my 2 cents,

Guckytos,

Thanks for your 2 cents. Feedback is always appreciated.

Imy wrote:I think fundamentaly there is a problem with magnification.. I'm beginning to understand. When I want to see moon after enlarging planet, well it is black and inside earth. This is the same problem as suggested with hubble. I think (quickly) that magnification demand to select system : for hubble the system is only earth and moon and then you can change final distance between them, no?

I wonder what does magnification : this algorithm has to be trigged just before that object is shown : it doesn't modify any parameters of object, do it? That's to say eclipses are still exact, distances information and other parameters are still exact in the left top corner...

Imy,

Actually, changing the distance between objects is not (yet) possible from Lua. Moreover, this is not the way magnification behaves on other astronomy softwares (Stellarium, Mitaka, ...). Magnification only changes the Radius of object. It's up to user to define a magnification coefficient that suits his/her needs. As an example, setting magnified_objects = "earth_moon" with earth_moon_magnification = 30, as it is suggested in config.lua, gives a quite interesting result.

Imy wrote:One reason for using enlarging object is to compare relative position of a point in a surface with another one which is on a reference object.
I'm wondering if in standard view, using arrows or vectors or bases would not be interesting to show, for instance, the rotation of planets on themselves Does exist a script for that?

Not sure I understand here. Can you provide a concrete example, please ?

selden wrote:or, maybe #4: provide "enable/disable magnification for the currently selected system" -- only changing the magnification for a system when mag/demag is explicitly changed while that system is selected.

Selden,

What you're suggesting is making the magnification checkbox keep track of the mag/demag state of each solar system, right ? I remember having briefly tried to implement this, but didn't succeed. That sounds interesting, though. So I'll give it a second try. Thanks.

or, maybe #4: provide "enable/disable magnification for the currently selected system" -- only changing the magnification for a system when mag/demag is explicitly changed while that system is selected.

That's a good idea : but it seems that you have to improve selecting system i think, haven't you?

One reason for using enlarging object is to compare relative position of a point in a surface with another one which is on a reference object.
I'm wondering if in standard view, using arrows or vectors or bases would not be interesting to show, for instance, the rotation of planets on themselves Does exist a script for that?

Wacthing planets (for instance) as great points is interesting, this is one reason for magnification. But like that, it's still only enlarging point. A second reason would be to point a particular place precisely on a surface (like my home! ) and compare its position with a particular another place on the moon like a crater. The aim would be to really see own rotation of objets. It would be a good instructive way to see in three dimension world how the trajectory of a location on rotating object is.

Magnification only changes the Radius of object

Does your magnification coefficient realy change the size for calculation or does this only change the size of the object at the end of processing, that's to say only for screen, for showing it? Can we still have eclipse shadows aright even if I've magnified?