Inserting a fictional star with custom texture into space?

[fsgregs]

In reviewing the forum, I discovered references to the possibility of inserting a fictional star into Celestia, using an ssc file rather than the star.dat file. If that is true, an ssc file could specify a customized texture for the star, rather than be limited to the O, B, A, F, G, K and M spectral class star textures called by the star.dat file. However, I thought you could only put a fictional star into orbit around an existing star (from the star.dat file) as a kind of "planet". I thought it was not possible to place a fictional star into its own position in space, so that it shows up as a star and not as a planet around some other star.
I'm confused. Please help!


Frank

[billybob884]

it is possible to make a star not orbiting around another star, you have to create an stc document. here is an example:

Code: Select all

# E-White
300010 {
        RA 84.119
        Dec -234.073
        Distance 500
        SpectralType "G1V"
        AppMag 10.34
}

you just put it into the extras directory. as for hte custom textures, i dont know

[selden]

Frank,

As Mike mentions, starting with v1.2.5, Celestia supports the textual definition of stars in files that have the extension (filetyoe) of .STC

My understanding is that the declarations in .STC files are essentially the same as the fields in STARS.DAT, just that they're textual instead of binary. At least some of them are listed in my cryptic file of notes at http://www.lns.cornell.edu/~seb/celestia/celestia-notes.html

Celestia still only has a half-dozen or so textures that it'll use for the images of stars, but, as you mention, you can overlay them with "emissive" planets with appropriately small orbits and large periods.

You might want to read through the thread where Rassilon revealed his "cluster generator" program for Windows. It'll create as many (or few) stars as you want in random locations approximating a globular cluster, along with some random planets. See the thread http://63.224.48.65/forum/viewtopic.php?t=1320

[fsgregs]

OK, great. I will be creating some stars, thanks to your help. Here is a thought. Would it be possible in 1.2.6 or later to use the Spectral Class code in the stc file to code for some new textures? For example, in addition to the usual OBAFGKM spectral classes, perhaps we could also "create" some "custom" spectral classes such as C1, C2, C3, etc. and somehow define those classes as customized textures. For example, a few of you graphics folks have created customized textures of white dwarfs, Red Giants, brown dwarfs and black holes. Perhaps 1.2.6 could define a custom spectral class C1 to signify a large Red Giant and define a custom texture for it. C2 could be White Dwarf textures. C3 = brown dwarfs, etc. Then, whenever I wanted to place a fictional Red Giant in the sky somewhere, I could use the stc file and either define it as an "M0" spectral class which would call the standard reddish star texture, or I could use the custom code C1. Celestia would then call the custom texture. It sure seems to save a lot of work over creating planet overlays in the same location. Considering that C1, C2, etc. can be literally infinite, we could keep adding new custom textures using only the star stc files. Is this possible?

Frank

[selden]

Frank,

While your suggestion does have some merit, I think I'd prefer a more generalized solution. Specifically, allowing any texture to be specified in the .STC files, just as textures are currently allowd for planets. One can hope that such an enhancement can be provided along with the inclusion of more generalized stellar information -- orientation, rotational speed, proper and radial motion, etc. Chris is very reluctant to add such things to the binary stellar database because of the increased overhead when millions of stars are involved. However, I think it would be reasonable to support such additions in the textual STC files, since (initially at least ) only a limited number of stars will be defined that way.

(Right now there seem to be some strange interactions when fake planets are used to provide the surface texture. On my system, at least, I can see the texture flickering off and on when the viewpoint changes. *sigh*)