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Forum » SpaceEngine » Feedback and Suggestions » General suggestions (Post your suggestions here.)
General suggestions
SpaceEngineerDate: Friday, 10.10.2014, 10:49 | Message # 391
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Quote Zaddy23 ()
Maybe it could be a ring texture up until a certain distance, then it replaces it with actual particles? I'm no programmer so I have no idea how this might work.

This didn't solve anything. You still need to store and compute the movement of all these particles.





 
SpaceEngineerDate: Friday, 10.10.2014, 11:27 | Message # 392
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FastFourierTransform, about your suggestions. Submoons, "circumbinary" moons, moons of asteriods, and procedural moons around catalog planets cannot be added in current architecture of the planet generator. It is simply too complex in the code. When I implement new simulation-based generator, it will be easy.

Asteroid rings could be added easily.

Number of planets in the system is limited by the initial size of the protoplanetary disk. SE didn't simulate young systems with intersecting orbits, and didn't simulate the Kuiper belt. Also, the Solar system browser would be hard to use, if the system will have 100+ planets.

Planets with extreme orbits cannot be implemented easy, because generator can't "clean out" their neighbourhood off other planets that intersect their orbits. This lead to colliding planets, which of course cannot be shown accurately in a procedural engine.

Real KBO catalog is already included in SE, as I said, and in the next version it would be enabled by default (because of upgraded catalog loader).





 
SpaceEngineerDate: Friday, 10.10.2014, 11:53 | Message # 393
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Quote FastFourierTransform ()
If the Solar System have had one more Gas Giants as Saturn this would porobably occur they conclude. So systems with many gas giants tend to highly eccentric orbits and instabilities:

Is that documentary on English available?





 
n0b0dyDate: Friday, 10.10.2014, 20:28 | Message # 394
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Hi, sorry if that is asked already:

- Would it be possible to add new galaxies and nebulae models in the galaxy and nebula model.cfgs to be used as procedural galaxies and nebulae and not affect numbering of procedural systems?

eg I have all Voekoevaka's galaxies added to galaxy model.cfg (together with their appropriate entries in galaxies10k.cfg) and have ''UseForType'' command in model.cfg enabled because if it is disabled that particular model will not be used for procedural galaxies afaik, but then all numbering of procedural stars in catalog galaxies change and I can not share a location I find because my SE universe is different from the ''clean'' SE universe with no addons.

In short: It would be great if we could add add-ons like new galaxies and nebulae to be used both as catalogs and procedural objects in SE but without affecting the numbering of procedural systems in catalog galaxies and ideally in procedural ones as well.

- 3D planetary rings should be possible because many othe spacesims have them e.g. Elite: Dangerous. I think they are using a technique where the same pattern of rocks is used again and again with some randomization so it doesn't look too repetitve. Also the rocks don't move in orbits - they only roatate around their axis in a similarly random pattern to give illusion they are moving. So if a similar techique is used for SE I think it would not require a supercomputer and should be doable. The trick should be to make SE think that all these rocks are one object (or at least a small group of objects) and not millions of objects. If this works then the possibility of having stars rotating around galaxy will not seem so impossible <--- probably wrong analogy smile

sorry if this is suggested before and for long post


Edited by n0b0dy - Friday, 10.10.2014, 20:32
 
SpaceEngineerDate: Friday, 10.10.2014, 22:12 | Message # 395
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Nebulae models does not affect the numbering. But galaxies models of course do, because changing the texture of the galaxy will change the shape of spiral arms, and because the star generator takes them into account, it will generate completely different galaxy. There is no way to bypass this problem, except ignoring the actual galaxy texture, but this is not a solution.




 
n0b0dyDate: Saturday, 11.10.2014, 08:59 | Message # 396
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Quote SpaceEngineer ()
because changing the texture of the galaxy will change the shape of spiral arms, and because the star generator takes them into account, it will generate completely different galaxy.


Space Engineer thank you very much for your reply!
Ok, understood but this should only affect the stars of the galaxy that the new texture refers to. Why does it affect the seed of all stars of all galaxies i.e. af all universe? For example if I add voevoevaka's galaxies, the numbering of Milkyway stars is also changed.
Sorry to ask too many questions...
 
FastFourierTransformDate: Saturday, 11.10.2014, 12:04 | Message # 397
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Quote SpaceEngineer ()
Didn't read all, I'm too tired now

Thanks for taking your time to answer me smile

Okey, by parts:

So Submoons, Circumbinary moons, asteroid moons, double asteroids, double moons and moons around the components of binary planets are imposible by now, but from what you said I infer that all of this amazing features will be implemented at the same time when the system architecture is changed no? Please, that would be amazing

Quote SpaceEngineer ()
Asteroid rings could be added easily.

oohhh that's great!!! smile

Quote SpaceEngineer ()
Also, the Solar system browser would be hard to use, if the system will have 100+ planets

But is necessary to change that right? I mean, maybe beyond the version 1.0 we could se that? Because that would be awesome! and relistic also.

Quote SpaceEngineer ()
Planets with extreme orbits cannot be implemented easy, because generator can't "clean out" their neighbourhood off other planets that intersect their orbits.

Oohh I understand. The issue of the planetary orbits with high inclination respect to the plain of ecliptic woudn't necessary intersect any planet but I comprehend the problem. Well, I only can say that if that problem is overcome one day it would be a giant leap also and would add much more variety to the experience. I see comets in SE that are in high eccentric inclined orbits but a planet with that kind of orbit is to much strange to be added maybe. Wow I would love to see this kind of changes!!

Quote SpaceEngineer ()
Real KBO catalog is already included in SE

Thanks a lot for the instructions


My part of the work

smile
Quote SpaceEngineer ()
Is that documentary on English available?

I've searched for the docuementary in other languages but I couldn't find it. What I could found is the papers and the researchers upon the issue of excentric giants is extracted the information in the documentary.
And I'm going to explain that in the next post, because is quite interesting and maybe with that you could get inspired on how to do the coding smile


Edited by FastFourierTransform - Saturday, 11.10.2014, 12:04
 
SpaceEngineerDate: Saturday, 11.10.2014, 12:11 | Message # 398
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The naming is based on galaxy number in the array. It change if you add or remove a galaxy from the catalog. It didn't change if you change the galaxy model or texture. But the seed used in the procedural generation is based on coordinates, not the name or number in the array. It changes only if you change the galaxy coordinates.




 
FastFourierTransformDate: Saturday, 11.10.2014, 22:30 | Message # 399
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I have spend a lot of time searching for accurate information and for writing this so please give it a chance and answer me when you are able to do so, it has been an entire day of work :)

Eccentric Jupiters
At that point, the documentary talks about the discovery of Eccentric Jupiters around many stars. The occurence of highly eccentric gas giants is incredibly high, so there must be a common explanation of why this kind of things occur. It appears that approximately 7% of all stars, where planets have been found, have an eccentric Jupiter (e > 0.1), making these planets more common than Hot Jupiters. This information is based in the fact that by 2006, of the more than 200 exoplanets known there where 15 Eccentric Jupiters. This is important because makes imperative for SE to have this kind of systems implemented soon to get much more accuracy in depicting the real world.

The study where the documentary relies has been made by Shigeru Ida from the Tokyo Institute of Technology in 1996 (so maybe is a bit outdated). The study is called "On the Origin of Massive Eccentric Planets" and it suggests that in sufficiently massive protoplanetary disks, several giant planets can be formed with masses in the range of 1 to 3 Jupiter masses. During all the formation period of this giant planets (within 10.000.000 years), the gas in the disk can be a dragging tool for stability in the system. But, after the depletion of the disk gas, mutual gravitational perturbation between the planets induces a gradual increase in their orbital eccentricities, until their orbits become unstable and begin to cross each other. The onset timescale for orbit crossing within a planetary system is sensitively determined by the planets' mass and separation, which may explain the diversity in the orbital properties among the newly discovered planetary systems.

From the paper we can extract this two images. In the first one we start with 9 Jupiters distributed in 1AU low eccentric orbits around the sun. The distance between the 9 planets increases by a factor of f=1,7. You can clearly see that 2.000.000 years from the dissipation of the protoplanetary disk the system gets extremely unstable. Some planets get scattered and other merge leaving a superjovian mass below the 1AU:


In this pic they show what would happen if instead of Jupiter, Saturn, Uranus and Neptune we have had four 2 Jupiter-mass planets located in the same orbits. We can see that after 6.000.000 years more or less the system gets extremly unstable and that 3 million years later the system has only 3 planets in very stable orbits. That's how eccentric jupiters are formed.


Highly eccentric systems tend to scatter other bodies so, only certain regions of the system are allowed to have stable planets in orbit around the star. This has been well investigated in a paper called "Dinamical and observational constraints on additional planets on highly eccentric planetary systems". In the page 7 and 8 of the paper you can see where those "zones of stability" for the search of additional planets. The stability is marked as an orbit that can survive more than 10.000.000 years without migrating. The study is made over the systems where eccentric Jupiters have been found. So here you can see that a system with this kind of eccentric giant planets have probably less planets and in very concrete zones of stability.

For example this image illustrates the natural selection of test particles in a vast range of orbits through ten million years in the HD 45350 and in the HD 80606 systems. The first one shows stable orbits inside the eccentric Jupiter periastron and the second one illustrates stable orbits beyond the apoastron of the eccentric Jupiter taking into account resonances etc...


As additional information to be taken into account when this systems are implemented on Space Engine, I have found a reasearch that has between its conclusions one that is important to note; The numerical results predict the existence of hot rocky planets (lava worlds) in eccentric giant planet systems.

In an international conference on exoplanets held at Vietnam this year, Shigeru Ida explained the eccentric Jupiters with this slides. In the papers that I have mentioned there is a clear relation between eccentric jupiter formation and systems with "too" many gas giants, and that correlates with the density, composition, mass and size of the protoplanetary disks where they form. In one of the slides Shigeru shows a graphic where there's an obvius correlation between the mass of the star and the mass of the disk around it. So we can say that there would be more eccentric jupiters in massive stars than in solar type ones:


I have found also a very interesting paper that characterize the systems with high eccentric jupiters and their evolution for more information and detail about this issue.

Inclined Exoplanets
For this argument, lets start from the Vietnam Conference of exoplanets held this year. Another disertation was made by Teruyuki Hirano where he talked about the inclination of the orbit of exoplanets from the equatorial plane of their host stars. It is quite astonishing the fact that many exoplanets exibit high inclinations with respect to their star rotations. There are even planets with retrograde orbits. The protoplanetary disk should have been in the same plane of the star's equator so there should be planets in that kind of orbits at the same time (maybe).


It's interesting to note that high obliquity orbits of exoplanets tend to occur normally with short period exoplanets.

So, there must be a mechanism to explain the frequency of this kind of orbits in the observational data. That mechanism it's advanced by this Oxford's research. In that paper, they explain situations in the early stage of planetary formation where the planets orbits may incline to even 90 degrees above the stellar disk!!!! The fact is that the constraints for this kind of changes in periods of time compatible with the end of planetary formation are that the planets must be, farther away from the "snow line" (where the giants formed).



<a class="link" href="http://arxiv.org/pdf/1404.3686.pdf" rel="nofollow" target="_blank">
In this paper they explain how the oscillations in the relative obliquity between orbits of exoplanets can increase the size of the habitable zone.</a> Interesting seasonal variations and ice ages by the way.

Trojan Planets
This issue was not explained before but I want to add it for discussion because is related to the problems you have with the planet generator of the program. If the limitations of SE code due to planets have to be defined when they create orbital gaps in the system, are overcome then we could add trojan planets.

The lagranage points L4 and L5 are stable points in the orbit of the planet. On those points there are masses ussually called trojan asteroids that live in strange orbital libration for billions of years without perturbation. The gas giants of the solar system hava a bunch of trojan asteroids in both L4 and L5. Even the Earth has a trojan asteroid. If a certain mass is concentrated in this regions (because of stability) then this lagrange points are important regions for the formation of larger bodies. In fact there are trojan moons for Tethys and Dione on the Saturnian system.

So there is a certain plausability for the emergence of trojan planets. When the problem of crossing orbits is overcome on Space Engine I would love to see two terras escorting a gas giant in the langrange stable points for example.

Hydrodynamical simulations of protoplanetary disks show that when a giant is created and the disk gets devoided of gas in that orbital gap it appers some acretion in the langrange points:


Here you have a paper related to the issue of detecting this trojan exoplanets escorting hot jupiters that may help undertandig the propieties and occurences of those planets.


Edited by FastFourierTransform - Saturday, 11.10.2014, 22:31
 
pile146Date: Wednesday, 22.10.2014, 20:42 | Message # 400
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Hello everyone!

I hope I am in a right tread for my following question/suggestion?

In one of the following updates (0.97.2...), is there maybe going to be a way to control your spacecraft in a same manner one controls the camera in "spacecraft mode"? So any ship imported or the default one could be controlled in the same way you control your camera in "spacecraft mode". Giving us a possibility to adjust the acceleration of the ship with the mouse wheel and with the benefits of rest of the Newtonian laws that "spacecraft mode" offers biggrin .

Maybe there is a tread or a suggestion like this somewhere on this forum, but I could not find it. If not here is one. Maybe someone can even make a mod for current version (0.92.1) that just attaches the ship model onto the camera? In my opinion I think this would be seriously fun user experience.
 
HarbingerDawnDate: Wednesday, 22.10.2014, 21:55 | Message # 401
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Quote pile146 ()
In one of the following updates (0.97.2...), is there maybe going to be a way to control your spacecraft in a same manner one controls the camera in "spacecraft mode"?

You can already do this. Open the console (~) and type "UFO". This will allow you to control the spacecraft using WASDRF, and using mousewheel to set any desired acceleration. You can also type "aero" and "gravity" to disable aerodynamic and gravitational effects to make it behave exactly the same as the camera mode.





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pile146Date: Thursday, 23.10.2014, 12:02 | Message # 402
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"Cheater" hahaha.

Thank you Harbinger!

This is exactly what I had in mind. Another level of fun in this amazing program. biggrin
 
SpaceEngineerDate: Thursday, 23.10.2014, 22:37 | Message # 403
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Quote FastFourierTransform ()
Eccentric Jupiters


First of all, they are not so common. Usually hight eccentric orbits reduces to almost circular when additional planets discovered around the star. So this effect is a lack of knowledge of full architecture of the system. Also, you have written: 7% of all stars, where planets have been found.

Quote FastFourierTransform ()
Inclined Exoplanets

As you have noted, this is relatively common only for hot jupiters, and explained by planet-planet scattering, the mechanism responsible for the hot jupiters formation.

Anyway, hi-eccentric and inclination planets should be of course, and the will be implemented in the new system generation code. Not in 0.972 though.

Quote FastFourierTransform ()
Trojan Planets

Actually, trojan points are semi-stable for planet-size bodies. They are stable only if the body have negligible mass compared to the star and main planet (ie asteroid), but this is not true for full-sized planets. The Tethys and Dione have asteriod-sized trojans too. Trojan planets can exist in young systems though - even Earth had a trojan planet Theia what had collided with Earth (due to instability of such configuration) and formed the Moon.

Anyway, you made a good research, thanks for links. On the Russian forum, I have a special thread where I collect links to articles related to planetary system architecture, formation and evolution. i am periodically refer to it when I made changes in the solar system generator code. If you have a account on the Russian forum, I would ask you to copy your post there, to have all in one place. Otherwise I can copy it myself.





 
HarbingerDawnDate: Thursday, 23.10.2014, 23:00 | Message # 404
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Quote SpaceEngineer ()
Actually, trojan points are semi-stable for planet-size bodies. They are stable only if the body have negligible mass compared to the star and main planet (ie asteroid), but this is not true for full-sized planets.

It can be stable for full-sized planets, it simply depends on the relative masses. A small planet like Mars could not have a stable trojan planet, but gas giants could support relatively large trojan planets and still be stable (at least, this is what Watsisname determined here).





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apenpaapDate: Wednesday, 29.10.2014, 11:40 | Message # 405
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Would the community compiling a list of catalog stars with wrong spectral classes (the giant orange and red dwarf stars) be any use to SpaceEngineer?




I occasionally stream at http://www.twitch.tv/magistermystax. Sometimes SE, sometimes other games.
 
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