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Distance units

Posted: Wed Apr 12, 2006 6:30 pm
by Ineptitube
While Oolite is realistic in many senses I have found it is so easy to pick holes in the physics
that it is not even fun. It is much more fun just to play the game. Which is as it should be.
I love it! I have concluded the game could not be so much fun if the physics made more sense.

But there is one quirk I cannot resist pointing out. I just cannot.

Next time you are at a witchpoint beacon press shift F. This brings up some information
including three numbers that are obviously x,y,z space coordinates. You'll see the witchpoint
beacon is out on the z axis. The sun seems to be out on the x axis and the planet is at the
origin.
Now using the enhanced scanner targeting system with the ship stationary find the range
to the witchpoint beacon (or you could use the navgation buoy or space station) and
record the three ship coordinates. Now move directly toward the target some distance and
again record the range and coordinates. Using the Pythagorean theorem on the
coordinate differences gives the number of coordinates you have moved and the difference
in ranges gives the number of km you have moved. This gives the number of km per
coordinate unit.
Now move to the planet and get as close to the surface as you can. Only a sliver of red
will show on your altimeter. Stop and use the Pythagorean theorem again on the coordinates
to get an estimate for the planet radius in coordinate units (assuming the centre of the
planet is at (0,0,0)). Get the value for planet radius in km from the information listed when
you press F7. This gives another value for km per coordinate unit.

Every time I do this the numbers of km per coordinate unit are different for the planet
than they are for the space station, navigation buoy or witchpoint beacon.

Posted: Wed Apr 12, 2006 8:52 pm
by JensAyton
The scale of Oolite makes no sense. This is because the scale of Elite makes no sense. We just have to live with it. :-)

However, the co-ordinates you’re looking at aren’t xyz co-ordinates, and they aren’t orthogonal, so you can’t use Pythagoras’ theorem on them directly. The co-ordinate system is “pwm”, or planet-witchpoint-something, where I think “something” is the cross product of the p and w vectors. I can’t remember what the origin is, but I’d guess at the station’s original position. These co-ordinates are obviously a bitch to work in, but they’re useful for specifying positions for OXPs.

Posted: Wed Apr 12, 2006 10:21 pm
by Selezen
pwm: planet, witchspace, metres.

Posted: Wed Apr 12, 2006 10:52 pm
by aegidian
Yes, you've just discovered that Oolite's planets, suns, and in-system distances are scaled down in size (relative to ship and station dimensions) by a factor of 100.

This is because combat and precise manoeuvring at relativistic speeds doesn't make for particularly enjoyable gameplay.

If you prefer a more realistic approach you could try altering the code to make ships and stations 100 times smaller (not particularly difficult to do), it'd be an interesting experiment to see if the game were anywhere near playable at such a scale.

Posted: Wed Apr 12, 2006 11:59 pm
by ArkanoiD
aegidian wrote:
Yes, you've just discovered that Oolite's planets, suns, and in-system distances are scaled down in size (relative to ship and station dimensions) by a factor of 100.

This is because combat and precise manoeuvring at relativistic speeds doesn't make for particularly enjoyable gameplay.

If you prefer a more realistic approach you could try altering the code to make ships and stations 100 times smaller (not particularly difficult to do), it'd be an interesting experiment to see if the game were anywhere near playable at such a scale.
Maybe just jump drive should be 10 times faster then?

Posted: Thu Apr 13, 2006 10:04 am
by aegidian
aegidian wrote:
If you prefer a more realistic approach you could try altering the code to make ships and stations 100 times smaller (not particularly difficult to do), it'd be an interesting experiment to see if the game were anywhere near playable at such a scale.
Just for S&G I tried this out. Ships are invisible until you get really close, then they go by in a flash (if you're lucky).

The unrealistic scale works far better.

Re: Distance units

Posted: Thu Apr 13, 2006 10:34 am
by TGHC
Ineptitube wrote:
Next time you are at a witchpoint beacon press shift F. This brings up some information
including three numbers that are obviously x,y,z space coordinates. You'll see the witchpoint
beacon is out on the z axis. The sun seems to be out on the x axis and the planet is at the
origin.
Now using the enhanced scanner targeting system with the ship stationary find the range
to the witchpoint beacon (or you could use the navgation buoy or space station) and
record the three ship coordinates. Now move directly toward the target some distance and
again record the range and coordinates. Using the Pythagorean theorem on the
coordinate differences gives the number of coordinates you have moved and the difference
in ranges gives the number of km you have moved. This gives the number of km per
coordinate unit.
Now move to the planet and get as close to the surface as you can. Only a sliver of red
will show on your altimeter. Stop and use the Pythagorean theorem again on the coordinates
to get an estimate for the planet radius in coordinate units (assuming the centre of the
planet is at (0,0,0)). Get the value for planet radius in km from the information listed when
you press F7. This gives another value for km per coordinate unit.

Every time I do this the numbers of km per coordinate unit are different for the planet
than they are for the space station, navigation buoy or witchpoint beacon.
You should get out more :wink:

Seriously though, it's contributions like this that help us all think more about how Oolite works, and how it can be enhanced