BodeDistanceStart, BodeDistanceEnd and eccentricity

[pixelfck]

I've a couple of questions on modding star systems.

What do BodeDistanceStart and BodeDistanceEnd do?
I've experimented with them but can't seem to get a clear picture of what they control.

What units does eccentricity use? does it accept floating point values?

Does the distance attribute accept floating point values? or do I need to specify the scale="pixel"?

And finally: can I make the center of an orbit accept offset somehow?

~Pixelfck

[Arisaya]

create a virtual world at the center you want, and spawn the new orbit as an orbit of that world?

[george moromisato]

I've a couple of questions on modding star systems.

BODE DISTANCE
This was original meant to implement Bode's Law for planetary spacing (https://en.wikipedia.org/wiki/Titius%E2%80%93Bode_law). In practice, however, I had to adjust the core constant to 1.35 instead of 2.0. It works like this:

Let's say you want to create 6 planets around the sun. BodeDistanceStart will be the radius of the first planet's orbit and BodeDistanceEnd will be the radius of the last planet's orbit. The planets in between will be spaced out such that the inner planets are closer together. The actual relationship is:

Orbital distance between 1st and 2nd planet = n
Orbital distance between 2nd and 3rd planet = n * 1.35
Orbital distance between 4th and 5th planet = n * (1.35)^2
Orbital distance between 5th and 6th planet = n * (1.35)^3

And the sum of all the above distances will be equal to the difference between BodeDistanceEnd and BodeDistanceStart.

ECCENTRICIY
This is a number from 0 to 99, which represents orbital eccentricities from 0.00 to 0.99. Unfortunately, it does not currently accept floating point values.

DISTANCE
Distance does not accept floating point values. The scale="pixel" is currently the best resolution. I should implement "megameter" (1,000 kilometers), which would be about 1/300th of a light-second. Pixels are currently set at 12,500 kilometers, but this is not guaranteed to be stable (though in practice it has been).

ORBITAL CENTER
You can use the <Offset> directive to adjust positions:

Code: Select all

...
<Offset xOffset="10" yOffset="-10" scale="pixel">
   <Orbitals ...
      <!-- the center of this orbit is offset relative to its parent -->
   </Orbitals>
</Offset>

MORE
The wiki has a stub article about SystemType:
http://transcendence.kronosaur.com/wiki ... systemtype

[pixelfck]

Thanks!

ECCENTRICIY
This is a number from 0 to 99, which represents orbital eccentricities from 0.00 to 0.99. Unfortunately, it does not currently accept floating point values.

Does this mean that I can specify a Kepler orbit with e between 0 and 1 with 2 decimals precision?

~Pixelfck

[george moromisato]

Thanks!

ECCENTRICIY
This is a number from 0 to 99, which represents orbital eccentricities from 0.00 to 0.99. Unfortunately, it does not currently accept floating point values.

Does this mean that I can specify a Kepler orbit with e between 0 and 1 with 2 decimals precision?

~Pixelfck

Yes, that's right!