Celestia Forums

I'm currently in the final stages in completed a ~190K script for Celestia I call "Celestia Explorer" which I plan to make freely available. I'm writing to make sure there are no copyright or other infringements. Unfortunately, why that might even be possible will take some explanation.

One of the things this script implements in an artificial intelligent entity that, among other things, can describe features of nearby objects. This information comes from a "type'" resource available within Celestia based on international standards. For example "AA" is a crater. Normally, I would simply write Celestia code to access that information and related info such as long, lat within the script, but that particular information is not accessible in this manner. Therefore, to solve this problem I wrote a program to read the resource file and translate that into a compact format that is stored in the data file of my program.

I'd like to stress that this is information that is publicly available anyway and I could have created the data file myself. The use of Celestia's resource file is simply a convenience that avoids me having to type in all the information. In fact this file will be augmented with other information pertinent to my program. The datafile will be used for no other purpose other than this script.

Henry

I have no problem with this. It would be nice to include a little note on where the data came from, as much for documenting your sources as for accreditation.

--Chris

hharris wrote:...
I'd like to stress that this is information that is publicly available anyway and I could have created the data file myself. The use of Celestia's resource file is simply a convenience that avoids me having to type in all the information. In fact this file will be augmented with other information pertinent to my program. The datafile will be used for no other purpose other than this script.

Henry

If some OpenSource database files from Celestia saved you work, it appears like a sign of good upbringing to say "thank you" in your forthcoming software...

You might not realize how much time went into a careful extraction of these data, for example. Noone over here is paid for this effort.

F.

I hope I didn't sound ungrateful. I realize that many, many hours must have gone into the compilation of this data and I'm very thankful to be able to take advantage of it. Of course my script will point this out with credit given.

BTW, in writing the parser for the locs.ssc files I noticed something. In the brackets for LongLat are actually 3 numbers, the third number always being zero. For example:

LongLat [ 175.2 -57.3 0 ]

Is the zero a place marker for a possible future upgrade?

Thanks again for creating a great program!

Henry

The third field is altitude above the surface in km.

The "surface" is a reference spheroid I assume?

Henry

hharris wrote:The "surface" is a reference spheroid I assume?

Henry

Reference sphere at the moment, but ellipsoids will be properly supported soon. At the moment, you can specify ellipsoid semi-axes and while they are used when rendering, an object is still treated as a sphere when calculating altitudes.

--Chris

chris wrote:

hharris wrote:The "surface" is a reference spheroid I assume?

Henry

Reference sphere at the moment, but ellipsoids will be properly supported soon. At the moment, you can specify ellipsoid semi-axes and while they are used when rendering, an object is still treated as a sphere when calculating altitudes.

--Chris

Actually this is in sync with the ISIS3 mission analysis tools that I am using for texture analysis etc besides my own F-TexTools/nmtools. ISIS3 only supports the spherical limit in case of SimpleCylindrical maps (as used exclusively by Celestia todate). Elliptical shape models are supported only for more fancy projections like Sinusoidal, Mercator,...

F.