On Orbits & Sun Distance

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Astrobe
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Re: On Orbits & Sun Distance

Post by Astrobe » Sat May 18, 2019 10:36 am

To me, the fact that the bodies are not moving while in the system is not a problem. Players are usually in a system an hour or two maximum, so I think the system's bodies don't have the time to move in a noticeable way.

IMO one should refrain from thinking in terms of distances and more in terms of travel times. In some situations, torus'ing to the sun can be as fast as going to the main station because of masslocks (OXZs not considered of course).

If the issue is to vary the system's configuration so that it doesn't always look the same, "all you have to do" is to rotate the planet around the Witchpoint. Sometimes it will lead to configurations sun-planet-wp conjunctions and the planet will appear like a black hole, but IIRC that's something that is already currently happen. And you can't call yourself a spacer if you're afraid of the dark ;-)

Also, one should not forget about rock hermits.

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Redspear
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Re: On Orbits & Sun Distance

Post by Redspear » Sat May 18, 2019 8:16 pm

Astrobe wrote:
Sat May 18, 2019 10:36 am
To me, the fact that the bodies are not moving while in the system is not a problem. Players are usually in a system an hour or two maximum, so I think the system's bodies don't have the time to move in a noticeable way.
I think it's more relevant when returning to a sytem, for example as part of a milk run. It's also a reason why I suggested that orbits could be reserved for moons rather than also applying to planets (can't remember if that was in this thread or another one...)

Astrobe wrote:
Sat May 18, 2019 10:36 am
IMO one should refrain from thinking in terms of distances and more in terms of travel times. In some situations, torus'ing to the sun can be as fast as going to the main station because of masslocks (OXZs not considered of course).
A fair point but as I said earlier, in at least some instances, greater distance = greater encounter frequency = greater masslock frequency.
Distance is more of a constant than travel time and so can be set.

Astrobe wrote:
Sat May 18, 2019 10:36 am
If the issue is to vary the system's configuration so that it doesn't always look the same, "all you have to do" is to rotate the planet around the Witchpoint.
As i understand it, when the system is generated, everything is set up in relation to the witchpoint. So in order to 'move' the witchpoint you actually have to move everything else. That doesn't invalidate your idea of course but once you're moving everything else to make it appear as if the WP is orbiting the planet then you're actually creating 'orbits' for everything else.

Astrobe wrote:
Sat May 18, 2019 10:36 am
Sometimes it will lead to configurations sun-planet-wp conjunctions and the planet will appear like a black hole, but IIRC that's something that is already currently happen.
Really? :shock:
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Astrobe
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Re: On Orbits & Sun Distance

Post by Astrobe » Sun May 19, 2019 9:45 am

Redspear wrote:
Sat May 18, 2019 8:16 pm
Astrobe wrote:
Sat May 18, 2019 10:36 am
If the issue is to vary the system's configuration so that it doesn't always look the same, "all you have to do" is to rotate the planet around the Witchpoint.
As i understand it, when the system is generated, everything is set up in relation to the witchpoint. So in order to 'move' the witchpoint you actually have to move everything else. That doesn't invalidate your idea of course but once you're moving everything else to make it appear as if the WP is orbiting the planet then you're actually creating 'orbits' for everything else.
Yeah, no. You can move just the planet if all you want is the illusion that things are spinning, not accurate orbital mechanics. Imagine the WP is the Moon (i.e., your reference frame is the Moon) and you look towards the Earth at all times:

https://en.wikipedia.org/wiki/File:Moon_phases_en.jpg

Everything that is not placed relative to the Planet/WP will seem to orbit them (in particular, the star) and you'll observe "Earth phases" too. That's what you'll see in game, because when you leave Witchspace the ship is always oriented towards the planet.

I'm not sure it is doable in OXZs though, or if it's doable without having to move everything placed relative to the planet (main station...) as well. The relevant code in the engine is in universe.m (setupPlanet):

Code: Select all

	[a_planet setPosition:(HPVector){ 0, 0, planet_zpos }];
The planet is set at a certain Z distance from the WP (which is at {0, 0, 0}). We could do something like:

Code: Select all

	[a_planet setPosition:(HPVector){ planet_zpos*sinf(angle), 0, planet_zpos*cosf(angle) }]; // not sure if it's actually correct, but you get the idea
... with angle depending on the in-game clock time (I assume the Y coordinate is "vertical" from the perspective of the witchspace-planet-sun plane, which is also the ecliptic of the planet?). This angle could also depend on a planetinfo.plist key that would default to a value such as the angle is always zero, in order to preserve the existing behavior. This key could be some sort of orbiting speed multiplier.

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Redspear
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Re: On Orbits & Sun Distance

Post by Redspear » Sun May 19, 2019 11:39 am

Apologies, I read that totally wrong...

I thought you'd said rotate the witch point around the planet (rather than the other way around), thus my talk about moving the witch point.
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Re: On Orbits & Sun Distance

Post by Redspear » Sun May 19, 2019 6:26 pm

Astrobe wrote:
Sun May 19, 2019 9:45 am
The planet is set at a certain Z distance from the WP.
Isn't the star also set by the same z distance (and then subject to sun distance modifier), just at a diferent angle?
If so, won't the planet be alternately closer and them further to the star by up to that same z distance?

That could mean (depending on how one sets up the orbit) that the planet has a range of z*2 in it's distance from the star and may even be in danger of colliding with it in the absence of a sun distance multiplier.

If I'm undestanding correctly (questionable at the best of times...) then I think it would need a significant sun distance multiplier just to avoid looking silly. For example, if the SDM were 10 then the planet would then range between 9z and 11z in distance from the star which might work.
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Re: On Orbits & Sun Distance

Post by Astrobe » Mon May 20, 2019 6:27 pm

No problem, my English may be lacking too.

The computation for the position of the sun looks complicated in the source. There's at least two or three configuration keys involved ( http://wiki.alioth.net/index.php/Planetinfo.plist ), but it seems to me that the computations work in our favor: the sun is placed after the planet, so it seems that the sun will be "pushed back" if we move the planet around (in the engine, not in OXPs).

You are right that it will incur distance variations which are probably the most noticeable in the default configuration (like in strict mode), but I believe those differences will be "hidden" by encounters and masslocks. As for the looks, in the default configuration it already looks silly in my opinion. With a sun distance multiplier, given that the basic unit is the planet's radius, there's no relation between the WP-planet lane length and the WP-sun distance. And empirically, the former becomes small very quickly compared to the later as you increase the multiplier.

An important side effect to keep in mind, though, is that moving the planet around the WP means that we can end up in the WP-Planet-sun (aligned) configuration, which is the worst case if you want to go from WP or the main station to the sun because you have to "walk around" the planet.

This looks good to me. I'm now interested in the general opinion on the idea, in order to know if it's worth trying to implement it.

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Re: On Orbits & Sun Distance

Post by Redspear » Mon May 20, 2019 9:47 pm

Astrobe wrote:
Mon May 20, 2019 6:27 pm
You are right that it will incur distance variations which are probably the most noticeable in the default configuration (like in strict mode), but I believe those differences will be "hidden" by encounters and masslocks. As for the looks, in the default configuration it already looks silly in my opinion.
With sufficient distance it needn't be a big problem... and I'm agreed about the default.

Astrobe wrote:
Mon May 20, 2019 6:27 pm
With a sun distance multiplier, given that the basic unit is the planet's radius, there's no relation between the WP-planet lane length and the WP-sun distance.
Er, I thought that planet radius also determined WP-planet length... then again that could (but needn't) mean that all planets would appear the same size on system entry (i.e. if WP-planet lane length were proportional to planet radius).

Astrobe wrote:
Mon May 20, 2019 6:27 pm
And empirically, the former becomes small very quickly compared to the later as you increase the multiplier
Either way, that's true.

Astrobe wrote:
Mon May 20, 2019 6:27 pm
An important side effect to keep in mind, though, is that moving the planet around the WP means that we can end up in the WP-Planet-sun (aligned) configuration, which is the worst case if you want to go from WP or the main station to the sun because you have to "walk around" the planet.
Assuming a standard planet-WP length and a significantly increased planet-star length then they wouldn't be travelling that much further to get to the star (pointless as it may seem in such a situation). As for the station, as long as it were a rare occurrence then it could even be interesting.

Astrobe wrote:
Mon May 20, 2019 6:27 pm
This looks good to me. I'm now interested in the general opinion on the idea, in order to know if it's worth trying to implement it.
My only real reservation at this stage is this one:
Redspear wrote:
Tue May 14, 2019 4:58 pm
So ideally, WP-Planet is reasonable, WP-Sun is not to big and Planet-Sun is not to small
The above aren't 'laws' but rather just my concerns.
As I understand it, your proposal necessitates WP-Sun being really quite big all of the time.

If the WP-Sun distance were not proportional to encounters along the lane (and such encounters were sufficiently few) then it needn't be a problem.
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Re: On Orbits & Sun Distance

Post by Redspear » Wed May 22, 2019 11:28 pm

Redspear wrote:
Fri May 17, 2019 8:22 pm
Suppose that rather than there being only one witchpoint that there were three, or even five, and each time you jumped into a system you were randomly allocated to one of these predetermined entry points. Very much different appearances are now possible and sunskimming could be affected also - we'd only need one of the entry point to be good for fuel scooping.

Because the entry points would be predetermined options then you needn't get awkward outcomes like the planet being hidden behingd the star. Furthermore, because your vantage point has moved, it becomes less obvious that each of the other bodies hasn't (given sufficient distance from each other.
Image


The method above still requires only three space lanes as only one WP ever exists, rather than all 5 at once.

In some instances distance to planet would be greater but distance to star would be smaller. For example, should you arrive at WP origin E after a long jump then sun skimming could be a no-brainer; arrive at origin A however and you may not wish to bother.

With a high sun distance modifier this could occasionally place the player very far from the planet and so encounter rates may need to be adjusted. If however, average encounter rates were set for WP position C then it may be that no further adjustments are necessary.

Pros:
  • Alternate views of the planet (50% - near 100% of player side lit in the example above)
  • Sunskimming viability occasionally very good (without shrinking planet to star distance)
  • All bodies are moved either in relation to the star and the planet or to the WP
  • Reduced likelihood of collision or close orbits with neigboring bodies (besides moons) that further betray the condensed scale
Cons:
  • Occasionally long trip to the station (balanced by occasionally shorter trips)
If encounter rates either remained constant (regardless of lane length) or were adjusted to match new lane lengths (e.g. reduced rate over distance and/or reduced variance over distance)then the above con needn't apply.
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Re: On Orbits & Sun Distance

Post by Rustem » Sat May 25, 2019 8:44 am

Redspear wrote:
Wed May 22, 2019 11:28 pm
..
Hi!

Issue a new version Orbits OXP 1.6.0:
- Added orbital offset for prevent the eclipse of the main planet.

---
  • Details: The Orbital Buoy was added for testing a views of the perspective and understand of orbital mechanics. Its will deleted in future version after testing in vary system's environments (the Distant Sun, or the Distant Stars, or the Sensible Sun and etc. OXPs).

    Triangle "Orbital Buoy - Main Planet - Sun" is orbital plane.
    Triangle "Witchpoint - Main Planet - Sun" is main (usual) plane. This plane is not perpendicular to orbital plane as planned early (above seen in the picture). Think, this is better and no trivial.
    This witchpoint's offset is need for prevent the eclipse of the main planet, when player entry in the system.
---

So, mainly, the Witchpoint is located in the Goldilocks zone like far moon of the main planet.

NOTE: This pack is consist errors (TODO):
- moons location for extra planets has not right location.
- also need fixed an orientate the station dock to planet direction.

I hope this is not offtopic.

P.S. I think sun skimming will use by pirates, smugglers and couriers(also by player in this roles). If they not found a near stations or a rock hermits in game moment, has't additional fuel tank, etc. The pilots with traders roles of course follow on the main spaceline.

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Re: On Orbits & Sun Distance

Post by Switeck » Sat Jun 01, 2019 7:30 pm

One other possible interpretation of where the witchpoint of a system is at...is it's in the same orbit as the main planet -- either leading or lagging it by maybe 30-60 degrees in orbit. The planet and sun of the system would remain in a relative fixed position to that and would look the same on every visit.
...At least for most systems.

The ones with the planet and sun overlap maybe closer to the Lagrange point just past the planet's orbit, but close enough to it that it retains roughly the same orbital speed as the planet.

Thargoids arriving in-system implies there's other destination points ships could arrive at, were they not locked to the witchpoint in their hyperspace computers.

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Re: On Orbits & Sun Distance

Post by Redspear » Fri Jun 07, 2019 9:36 pm

Switeck wrote:
Sat Jun 01, 2019 7:30 pm
One other possible interpretation of where the witchpoint of a system is at...is it's in the same orbit as the main planet -- either leading or lagging it by maybe 30-60 degrees in orbit. The planet and sun of the system would remain in a relative fixed position to that and would look the same on every visit.
...At least for most systems.
Isn't that very similar to what we have already in the default game?

Rustem wrote:
Sat May 25, 2019 8:44 am
I hope this is not offtopic.
Not at all, highly relevant I'd say :)

Not sure I fully understand your explanation but I look forward to trying it out, Thanks!
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