Vega Strike Forums

Does VS use any particular units sceme (e.g. SI, metric, etc) for system orbital parameters? I've been trying to remodel the VS Sol system to use real-world orbital data but I haven't been able to make much headway in figuring out how to massage the various orbital parameters into something that works with VS.

Does the year parameter have anything to do with orbital velocity or is that determined exclusively from the r and s vectors?


Along these lines has the project given any thought to remodeling the VS universe to use more realistic planetary distances? The present model has a few problems, such as the fact that it's not possible to get to some parts of the VS universe because there is a planet or two in the way. Spacing everything out to realistic distances would eliminate most all of this problem. Further, places like Heaven's Gate also look a little silly when one can do a trade run between Barnoose and Nief simply by turning your ship around.

For an example of what (extremely) realistic orbital paths look like, take a look at Celestia.

hey...

VS actually in CVS uses more realistic planet distances....
well we multiply the distances by 16...more than that and you can't see any of the planets but the one you're near (why keep track of them then!)
so we make them just barely visible...

anyhow VS uses meters

Ri is the farthest point of the orbit
Si is the nearest point of the orbit (vector x,y,z in meters)
I think there's a centerx centery and centerz which can offset the centroid of the orbit (not sure if that's implemented in anything except the CVS version)

year is how many seconds the planet takes to make one orbit.

now the CVS version of VS has more realistic distances and thatshouldn't be a problem any more
if you can get minimalistE at http://hkn.eecs.berkeley.edu/~daniel/minimalistE.zip then yuou can experience hte new stuff yourself I *think*
at least you have to copy the old data over the minimalist stuff

hmm.. The way I make systems, the planets don't even have realistic distances or have realistic sizes. I dunno. I'm afraid that I might get some overflow error.

VS is designed to handle large system sizes...I had to hack some lower level matrix stuff in the OpenGL method of handling matrices...but it ended up paying off and I got huge resolutions
there's no such thing as an overflow error with doubles....

if you made your thing have hundreds of digits then it might snap to #INF, but there's no "error" per se...try it to see

hellcatv wrote:anyhow VS uses meters

hehe...I think anyone who has tried to work with VS has realised that yes, somewhere doen deep VS uses metres, but everywhere else you've got to take into account all the (apparently random ) multiplications to get the actual sizes/distances you need

to get everything as 1 unit (for you modders)...just cnahge all the weird multiplications in the config file to 1.....at least that changed everything I could see back to normal

Dan.a

hellcatv wrote:Ri is the farthest point of the orbit
Si is the nearest point of the orbit (vector x,y,z in meters)

Ah. That would explain a few things. I was going by the information in the Wiki, which defined S as something other than the apsis (perihelion).

if you can get minimalistE at http://hkn.eecs.berkeley.edu/~daniel/minimalistE.zip then yuou can experience hte new stuff yourself I *think*
at least you have to copy the old data over the minimalist stuff

The last minimalist I grabbed didn't include any system data files.

Enlightenment wrote:

if you can get minimalistE at http://hkn.eecs.berkeley.edu/~daniel/minimalistE.zip then yuou can experience hte new stuff yourself I *think*
at least you have to copy the old data over the minimalist stuff

The last minimalist I grabbed didn't include any system data files.

If you have enough bandwidth free you can download the cvs-data and copy the minimalist stuff over it. (it's worth it )

Pontiac

hmm, i think, we need to finally resolve the distances and unit scale issue...

this cant keep popping up..

-scheherazade

Hi all,


I ask in this thread for sake of simplicity, since it's linked from the wiki page at "HowTo:Edit_Systems:System_Files".

My question is about positionning an orbit. You have (rx, ry, rz) and (sx, sy, sz), that's right. But 2 points are not enough to make an orbit. You plot the line between the points, find a reference upside direction somewhere, then you have to input an eccentricity and an angle from the reference upside direction. As the dataset in .system files is described in the wiki, these parameters are nowhere. So how are they computed ?

Thanks in advance for any answer !

Actually, they are enough - they're not two points, but two vectors.

The two vectors, along with the orbits' geometric center which is implicit because of the heirarchy (you can see how a moon is defined under the planet's tag, then the planet is the moon's orbit center).

Orbits are ellipsoid and not truly elliptic, those two vectors aren't foci, but parameters for the equation:

Xt = rsin(t) + scos(t) + x0

Where x0 is the parent unit's center.

Vega Strike doesn't need any more accuracy than that, IMHO, since orbits are usually slow enough that they can't be directly observed ingame. (and the game doesn't strive for accuracy as celestia does).

Hi klauss,


OK, I understand better ! That's indeed the simplest way to define an orbit.