Celestia Forums

Your add-on is very useful for an astronomy program! It could allow to show more information about any object in universe...Thanks.

Because the Solar System is already full of add-ons, I've thought of re-creating the Sol system at approx 35 ly from Aldebaran

I don't know a lot about Celestia code, but i think it's surprising that if you can have alternated surface option, you could not have alternated model solution that would avoid you to create an artificial planet system which can be misunderstood by anyone would not be a specialist in astronomy.
I feel that your add-on should be integrate in Celestia basic package!

Thanks Tharghana and Imy for the comments and I apologize for delay in reply but my job in this moment take me away from whatever computers. Just now I've found an Internet point.

For Tharghana: Gas Giant are on my log, although until now I've found just only poor detailed schemas.

Imy wrote:Your add-on is very useful for an astronomy program! It could allow to show more information about any object in universe...Thanks.

Because the Solar System is already full of add-ons, I've thought of re-creating the Sol system at approx 35 ly from Aldebaran

I don't know a lot about Celestia code, but i think it's surprising that if you can have alternated surface option, you could not have alternated model solution that would avoid you to create an artificial planet system which can be misunderstood by anyone would not be a specialist in astronomy.
I feel that your add-on should be integrate in Celestia basic package!

An alternate surface which shows the break from a complete sphere it's no so simple because in Celestia the texture mapping is global, so I should may do the containers even for the text (two containers, one for the text black and one for the text white as well as the planet itself, because they would be first invisible and then visible with one general colored texture for each meshes, which would affect also the container(!); so, this latter would be hide beneath the rest... I hope to be clear in this discourse, sorry ), and then this model would substitute the default Celestia's spheroid in the main solarsys.ssc; thing that is quite deprecable. Without counting the raise of polyhedrons... Mind that in 3ds format Mercury, for example, is just 880 kb. With the Bodyfixed directive one can avoid the text's containers, but for my personal road map, in this add-ons I wish maintain the downward compatibility.

and then this model would substitute the default Celestia's spheroid in the main solarsys.ssc; thing that is quite deprecable.

I understand now why all add-ons are built far away in space, in an empty area.
But some add-ons like yours, would be integrate at their place, instead of earth and other planets. What I mean is that Celestia would have an option like alternated surface (that already existed) to change models. For instance, I have Basic Earth, I click with right mouse button, the pop-up menu is shown and I change with InsideEarthModel...

I really love these interior planet addons, but I could not help but think that there is a better way to make them. Something easier to implement, easier to update, and smaller is size. I was just looking over on wikipedia http://en.wikipedia.org/wiki/Mercury_(planet) and then it struck me. How difficult would it be to implement a SVG overlay for a planet, based up camera view? The overlay would look something like this
http://upload.wikimedia.org/wikipedia/c ... ucture.svg minus the grey sphere layer; so it only shows the internal layering.

There are some advantages and disadvantages to this.

Advantage
The planet can rotate and it would not affect the structure.
You could implement a location based system to define the layers instead of static text.
Smaller size, simpler structure and should be easer to modify.
Unlimited zoom capability.

Disadvantage
The angle of view would be static no mater what.
Animation

It's a suggestion to show local photograph (or more information) : What about interactive mouse pass over circle?
You move your mouse pointer on this special circle and then a rectangle grows up like a balloon tool boxes. Is it possible in Celestia today?

Fenerit,

your mars_interior model is really beautifull. There are some problems with the model in Celestia, however ("blinking" effect of some parts, which are too close to other parts). And some invisible parts inside the sphere could be deleted.

Since I'll have to talk about Mars, in my astronomy courses, I'll need a French version of a similar model. So I decided to built my own version, using the same data as you. Here's a preliminary *test* version (using a texture from your addon, which I'll change later since I don't want to use your own work. Please, read the comment below). Click the thumbnail to enlarge the picture :



I'm really sorry to have to copy your model, and I don't want to interfere with your creation. I hope you wont feel offended by my intrusion, and I certainly don't want to steal the idea from you and the opportunity to present a similar model. So please, if you feel annoyed by my own version, just tell me by PM and I wont publish my version. I'll understand.

Here's the model and its textures finished. I only have to add the text layers (probably in a separate model) :



The final model wont have as much details as Fenerit's version.

Here's a view of the state of my Mars model. It isn't finished yet :

Here's a view of my final (?) version. I don't see what else to do on that model.

Next step would be to create some interior model of the Sun and Mercury. In the case of Mercury, it could be fun to have a model similar to this prototype :



in the same spirit as this model :

http://upload.wikimedia.org/wikipedia/c ... ucture.svg

This is harder to do, though, since it's preferable to make the model from a single piece, like this one (NO boolean functions, and the match must be perfect) :

This is alot of really neat work. I wish I had stuff like this back in my astronomy class in high school.

Okay, I wasn't able to resist. So I made a model of Mercury with the right proportions of the layers (the data used will most probably become obsolete in the following 2 years, with new data from Messenger) :



The shape of this model should compensate for the lack of interest since there isn't much to see, from the available data. So there's a crust (thickness of 100 km), a rocky mantle (probably solid), and a large liquid (?) core made of iron and nickel (75% of the planet's radius).

Here's the state of my Mercury model (the previous free image host seems to be offline, so I'm using another one. The image quality appears to be changed ) :

%$#@& free pictures server ! Pictures are gone.

Cham wrote:%$#@& stupid free pictures server ! Pictures are gone.

Can you use Google's Picasa (picasaweb.google.com)? I think they give you about 50 megs for free.

--Chris

Cham wrote:Goddam%$#@& stupid free pictures server of $hit ! Pictures are gone.

Nothing in life is free... Why don't you put a crowbar in your wallet and
pay for quality service? My web site (with Time-Warner Cable) actually
gives me free web hosting with my account, and I only have to pay a
few bucks more if my site is accessed more times than is reasonable
during the month.

Sorry, but I just don't understand why everyone wishes to mess
with these supposed "Free" sites. waste of time in my opinion. First,
you get crappy service, second you're usually inflicting advertising on
your visitors (which they do NOT wish to see) and finally you have
absolutely NO control over the content. Why bother?

Another thing... Why don't you say what you REALLY think here.

Hi, There! Found another harbour with web connection just now.

Cham: First, welcome back from India! Second, you can use whatever you need from my models for free and educational purposes as well as following common speciments. I should like to see that another people make and share it's owns interiors. The blinks that you said I acknowledge which matter are, because I've found them in my first version of Mercury and depends upon the distances from the meshes one to another, often they shows itself when are a little raised respectively as well as with more consistent value of spissitude, but in the case of Mars I've accurately tested the model to avoid this behaviour and for my graphic configuration all work fine; so, in this case I do not have idea of why. Same thing for the "invisible parts" inside: what they are? The model is just a boolean sphere with three disks! The breaks perhaps could be made with NURBS modelling but what happen when shoutdown in polyhedron? Now I do not have time and machine to try this. Your Mercury model is beautiful, but I do not see the rest of the pictures!

Imy: For a quick solution of your issue, read the fist page of this thread; there is an explanation on how you can do. Remember just to manually assign the normalmap texture to the sphere (in CMOD format, nor 3ds) which will desappear once the altsurface map's operation will point to the interiors, if you want the bumps; anyway, you will lost the VT feature.

MKruer: Nothing to say here; it's a Chris response.

Johaen: It's the fate of geology: hard rock is too hard to handle.

Here's how I build the planetary interior models. No boolean operations are needed.

1. First, I make a sphere of 1 unit radius, and choose a proper resolution for it. I will need to select some even number of polygons, so I can remove easily 1/8 of the surface, so beware of the resolution of the sphere. In this example, I used a sphere made of 60 longitudinal sections X 40 parallel sections. For a real model made for Celestia, I prefer to use an higher resolution, like 120 x 80 polygons, so the sphere appears smooth at close range) :


2. Then, I select the parts I want to remove (1/8 of the surface) :


3. Erase the polygons :


4. I add an internal sphere to make the core, with the same resolution as the bigger sphere (this isn't necessary, but helps a lot to ease the bridge process described below. See step 7). Of course, all internal parts should be made to scale, knowing that the external sphere has 1 unit radius :


I made a small error in this example, when I selected the polygons before I erased them (see the glitch on top). Be carefull with the selection process.

5. I remove 7/8 of that core, with the same process as 2 and 3 above :


6. I then combine both parts into the same object (your modeler certainly have an option to do this, witout using a boolean function) :


7. I use the "bridge" tool (or "join", depending of your modeler), to joint both parts :


That way, the match should be perfect, and there wont be any hole left, after you separate the parts (for proper texturing).

8. I select the mantle part (using a "ring select" tool), and separate it from the rest (using the "split" tool of my modeler) :


That way, the match is still perfect with the other piece and I can easily apply a proper texture on the mantle. Now, I have two separate pieces.

9. Selecting the external sphere, I separate it from the internal one ("split" tool again). So I now end with three pieces which are looking like a single piece (perfect match) :


To build the crust, I simply repeat the process described here with several spheres of proper radius, and use the "bridge" tool. After, I simply select a part (the crust, say), and separate it from the rest ("split" tool again, in my modeler), so I can apply a specific texture on it. So, I have a separate piece for the surface, the crust, the mantle and the core. All pieces are matching perfectly (no holes, no defects, and no invisible polygons), and I can apply a different texture to each one of them.

It's easy, pretty fast, and never give holes or defects, so characteristic of the boolean operations.

Thanks a lot to ElChristou, for holding the pictures on his personal server.

Depending your soft, a faster way is to select the shell you want (here 7/8 ) and extrude it in one step:

LOL, good trick. Unfortunately, AFAIK, my modeler doesn't give a good control on the size of the extrude, so I can't have the right proportions for the layers. And it's also giving some very wrong deformations of the mesh, when the extrude is strong.