Celestia Forums

Apparently Celestia is one of the favorite visualization programs of the people designing new space missions at the European Space Agency: http://www.esa.int/gsp/ACT/mission_analysis/designtool_overview.htm It is listed first, and the description is: An impressive visualization tools for interplanet...

Some time back, I experimented with some atmospheric effects in celestia - "star twinkling"; so to speak. As Celestia already determines if and how deep the observer is inside an atmosphere, it was quite easy (~3 loc) to scale this "twinkling" effect. It could also be used to superimpose other atmos...

Short idea for Sensible Improvement of Interface: - Set center of orbit display As I understand the orbits could simply be resampled (using the relative position to the reference object/position) and centered on the reference. (Additionally, the orbit of the central Star would have to be drawn) This...

Bodies and Stars: The original issue with stars is that there are literally millions of them. Even if subclassing takes only four bytes per star as additional type information (original argument made by chris somewhere in the code or doc) the overhead would be significant to say the least. Additiona...

Concerning the "forking" of an FLOSS projct, I ran across an interesting description by David A. Wheeler: http://www.dwheeler.com/oss_fs_why.html#forking

[quote]
Many OSS/FS projects (such as the Linux kernel development project) intentionally have ?€?fly-offs?€

another interesting observation: If they rotate at the beginning relative to each other, depending on the masses and the distance, they begin to lock their rotation (around the individual axis) with the revolution around each other, so only one side is visible form each other. this is due to tidal f...

If this were true, we would obviously see dark matter mostly there where there is no other matter. But quite on the contrary, we notice that the distribution of dark matter is rather similar to distribution of normal matter. The discovery of VIRGOHI21 is so interesting because it is the first occure...

Another very notable IDE is Eclipse this is an Open Source project started by IBM, originally for Java and now (with the CDT) for C/C++ http://www.eclipse.org Available for Linux, Solaris, AIX, Mac and Windows (or anthing with a Java VM). Has a class browser, outlines, autocompletion, works natively...

@Slaloms8er: Alls Stars emit a well-understood spectrum that is called Black-Body radiation http://en.wikipedia.org/wiki/Black_Body This spectrum _only_ depends on the temperature, so the information present in celestia - and the implementation, as t00fri said - is sufficient to produce images in _a...

Starting with Stars: Stars are relatively easy to model spectrally, as they can be approximated pretty good by "black body radiators" (or the english equivalent) i.e. the intensity of the emitted radiation per wavelength is an analytical expression depending only on the temperature. As celestia (and...

Not yet able, but willing. Will see what I can do.

Apollonian: The Multi-step methods I use are said taylor expansions, the higher-order terms are approximated by interpolation of multiple previous approximations (in my case three previous values). In contrast, Runge-Kutta uses only the last value; so in the multi-step method I first use Runge-Kutta...

One further comment on the free software approach taken by celestia: In my project (numerical simulation of bodies in gravitational fields) i can easily use celestia for visualization by simply creating another orbit-type (in the code); I couldn't do something like this with a closed-source (i.e. li...

At the moment it is based on a dynamic-step classical Runge-Kutta method (to scale), but I'm actively chasing for a certain book on energy-preserving Algorithms for ODE's, I'll get that propably on monday. I also had a look on some course material on multi-step methods (?), i.e. using the last three...

Introducing classes in SSC files is principally a good idea, yet I think this should be planned as expandable as possible. There exist two possibilities: Add the possibility to name Structures in arbitrary ssc-files and then reference them when needed Add "real" classes that are reflected in the sou...

I have implemented a small addition, a dynamic Orbit class that simply causes an Object to be influenced by gravitation. There is a provision for a Mass field in the scc files, but nobody seems to use it (at least for the planets), so I have to add that manually. When I have it working better, i'll ...

Problem is that you have to have at least a list and positions of the Objects im memory to calculate a line of sight.
But perhaps Chris could enhance his Octree system so that ist caches unused branches on the hard drive, although that would be slowwww

1st: Increase it by one :-) then append 25 bytes: 4 bytes with a hipparcos catalogue number (int32) 4 bytes with a "HP" catalogue number (also int32) 4 bytes (float) with the rectascension (<- is this spelled correctly?) 4 bytes (float) with the declination 4 bytes (float) for the parallax 2 bytes f...

It's not too difficult if you can program (see thread http://www.shatters.net/forum/viewtopic.php?t=277 ) I am already working on a semirandom star generator that can simulate the galactic distribution of stars, but I think for new creations (planetary systems... ) real stars would be better. (Think...

Adding Planets & Moons is quite simple - just make a new .ssc file in the extras directory and add Planets/Moons like this: "nameOfTheNewPlanet" "Starname" { Texture "texturefile" Radius 2440 CustomOrbit "yourplanet" EllipticalOrbit { Period 0.2408 SemiMajorAxis 0.3871 Eccentricity 0.2056 Inclin...