Celestia Forums

I'm sorry if this has been asked before because I can't think of good keywords to search this concept but I'm at a lost for how to do this. What I want to do is position the observer between two celestial bodies A and B such that it is looking at B with A directly behind it and if there was a line i...

Wow! Well, I just installed 1.5.1 since 1.4 was on a different partition on this OS X box and I could not run it off of that partition (probably because the CelestiaResources (as we call it here in Mac-Land) was not in the correct path anymore). So, first of all, let me say I 100% agree with Qt. I h...

Looking some more at the code, my opinion is that the best thing to do is solve the problem in 2 steps: 1) Typedef double JulianDayNumber; and replace double with JulianDayNumber throughout the code where a double is used to represent a Julean Day Number. 2) Design a class that emulates a double wit...

Celestia uses Astronomical dating, not Gregorian. See http://www.hermetic.ch/cal_stud/cal_art.html for a description of the differences between Christian Gregorian and Julian calendar systems and the Common and Astronomical calendar systems. Thanks Seldon. I am fimiliar with what is commonly called...

If you use 'long long' in the astro::Date::Date(double jd) constructor in src/celengine/date.cpp, you fix the current year rollover, but you still run into the cloud bug at 32559280-11-26 22:23:15. Sorry, what's the "cloud bug"? As far as JDN (Julian Day Numbers) are concerned, those only count day...

I like the idea of being able to express a broader range of time. However, I would suggest the following (as I have done in the Physics/Astronomy thread): Year should express a 64-bit number for dates in that range. The would easily cover all of Universal history from a period so long before the big...

Thanks Fridger, I read the discussion and like the idea of co-moving coordinates. Indeed, you bring up a few fascinating issues that remind me how interesting things could be. Namely, I think that your Gott et al. -style 3D transform sounds cool, although I'd probably not set the origin at the cente...

I am looking at the Celestia source (1.4.1) and it looks like most of the work would be in simulation.cpp and render.cpp for Relativistic motion in an accelerated frame and render.cpp for Gravatation Lensing. Also, astro.cpp for extending time to the Geological and Universal scale. Time IMHO should ...

After discovering the great (but small) texures at http://jan.ucc.nau.edu/~rcb7/RCB.html that Brendan pointed to on the Pangea threat , I've decided to do a little homework and provide these as an addon to the community. Can anyone tell me where to get Maxim's add-on and the add-on for Earth during...

The SSC Beginning and Ending directives specify when an object should be drawn by Celestia. You just need to define the different objects with everything identical except for their textures and Beginning and Ending times. Oh, cool! So then I say Moon exists from say -50 My to +50 My at distance fro...

I was thinking of making a plugin that would change the image of certian objects, such as Earth, depending on the time read on the clock. I.e., if the time is -250 My then I would show Earth as an image of Pangea, where as -500 My I'd show the continent of Baltica. So the idea would be, I need a cal...

Okay, going back over the Lorentz contractions, I would suggest the following in terms ONLY of spacial orientation. I may cover blue/red shift in another post but as hinted at, the faster you go, the shorter the wave lengths become and at c its worse than GoogleWatt Gamma rays. From a radial point o...

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