Blank stars.dat file?

The place to discuss creating, porting and modifying Celestia's source code.
Topic author
Evil Dr Ganymede
Posts: 1386
Joined: 06.06.2003
With us: 21 years 5 months

Blank stars.dat file?

Post #1by Evil Dr Ganymede » 13.12.2003, 09:35

I think this was mentioned a while ago... but is there such a thing as a blank stars.dat file? The idea would be that this makes it possible to load a 'blank universe' that one can fill up with one's own stars and planets, which would be kinda useful for those of us who would be interested in using Celestia as a visualisation tool for sci-fi RPGs or other similar projects.

I'd like to write a review of Celestia for an online magazine devoted to a sci-fi pen-and-paper RPG (Traveller), and the existence of a blank stars.dat file might make it more attractive to people there (since it makes Celestia that much more customisable).

Cormoran
Posts: 198
Joined: 28.07.2003
With us: 21 years 3 months
Location: Slartibartfast's Shed, London

Post #2by Cormoran » 13.12.2003, 10:30

Interesting point, Dr. G.

As an aside, most RPG's use either a 2D mapping method (like Traveller's sector maps) or a 3D method defined in xyz co-ordinates.

I suppose one could generate .STC files using such data by writing a program that reverse engineers xyz or xy data into faked Right-ascension and declination data.

Just a thought.

Cormoran
'...Gold planets, Platinum Planets, Soft rubber planets with lots of earthquakes....' The HitchHikers Guide to the Galaxy, Page 634784, Section 5a. Entry: Magrathea

Topic author
Evil Dr Ganymede
Posts: 1386
Joined: 06.06.2003
With us: 21 years 5 months

Post #3by Evil Dr Ganymede » 13.12.2003, 10:54

Cormoran wrote:Interesting point, Dr. G.

As an aside, most RPG's use either a 2D mapping method (like Traveller's sector maps) or a 3D method defined in xyz co-ordinates.

I suppose one could generate .STC files using such data by writing a program that reverse engineers xyz or xy data into faked Right-ascension and declination data.


The thing about Traveller is that while the stars around Earth vaguely tally with real stars, it gets out of sync with the real universe very quickly beyond the immediate vicinity of Terra. If one wanted to make a Celestia version of sector map of the Solomani Rim sector - never mind the 2d mapping problem - then most of the stars just wouldn't match at all with what's in Traveller canon.

That's why having a blank stars.dat file would be so useful from that point of view - it could allow you to (with a lot of work writing STC and SSC files) fill up an entirely new universe with systems and objects in any place you wanted them to be. That makes it a lot more attractive for roleplayers and worldbuilders.

Cormoran
Posts: 198
Joined: 28.07.2003
With us: 21 years 3 months
Location: Slartibartfast's Shed, London

Post #4by Cormoran » 13.12.2003, 11:21

I agree completely Dr. G.

I must admit it would be extremely cool to fly around the Spinward Marches!!

It might be rather fun to put in some of the classic Traveller ships as models in orbit around Regina. Should be quite simple to build them.

As a 2300 AD officionado, I've been toying with the idea of going through the Colonial Atlas and Invasion! sourcebooks and putting those systems together, though I digress.

As for classic Traveller mapping, my comment still stands. Given that Celestia only reads Right Ascension/declination data, conversion would still be required, though the trig would be a lot simpler, though converting the data so the Galactic core is in the y axis is gonna be fun. Guess its time to get out the ruler :lol:

Regards,

Cormoran
'...Gold planets, Platinum Planets, Soft rubber planets with lots of earthquakes....' The HitchHikers Guide to the Galaxy, Page 634784, Section 5a. Entry: Magrathea

granthutchison
Developer
Posts: 1863
Joined: 21.11.2002
With us: 22 years

Post #5by granthutchison » 13.12.2003, 18:07

Hmmm. I've edited stars.dat down to a single entry (4 bytes containing the long integer 1, 25 bytes with the definition for Sol copied from the original stars.dat) - that's what Chris suggested in the orginal thread, but it seems to make Celestia crash on start-up.

Grant

Topic author
Evil Dr Ganymede
Posts: 1386
Joined: 06.06.2003
With us: 21 years 5 months

Post #6by Evil Dr Ganymede » 13.12.2003, 19:26

granthutchison wrote:Hmmm. I've edited stars.dat down to a single entry (4 bytes containing the long integer 1, 25 bytes with the definition for Sol copied from the original stars.dat) - that's what Chris suggested in the orginal thread, but it seems to make Celestia crash on start-up.


Even having Sol there might be too much :). I wonder if Chris is reading this, or if I should PM him about it? Either way, I think it'd make the program more versatile to be able to start without a stars.dat file.

Topic author
Evil Dr Ganymede
Posts: 1386
Joined: 06.06.2003
With us: 21 years 5 months

Post #7by Evil Dr Ganymede » 15.12.2003, 18:15

*bump*

So, is this just totally impossible to set up?

Topic author
Evil Dr Ganymede
Posts: 1386
Joined: 06.06.2003
With us: 21 years 5 months

Well, *that's* odd...

Post #8by Evil Dr Ganymede » 16.12.2003, 08:23

Sorry to keep going on about this...

I found something called CStarsConv on the web which apparently compiles stars.dat files, so I tried converting the existing stars.dat file into text, editing it down to a couple of stars, and back into a stars.dat file.

If I deleted all the stars except the first one and Sol, Celestia wouldn't open and got an illegal memory reference error.

If I deleted just the last star (not Sol) - or even just converted the default stars.dat to text and back without making any changes - then Celestia did work, but I ended up with a Sol that was about a lightyear across, encompassing the entire solar system! Which was very odd, especially in the case where I didn't change anything.

So I guess this program doesn't really work? And presumably there's no other way to edit the stars.dat file?


Return to “Development”