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Mosfet
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COMMUNITY ADDON - Double/Multiple Asteroids fixes for SE

12 Apr 2017 17:15

If I understand correctly, you are noticing that according data info regarding s2002 (3749) 1 we see it as having 2 moons, while Balam data shows none. Let's see to figure out a reason why it says 2 moons.

 Balam and Litva are both triple systems, where we have 3 objects and 2 relative barycenters.
Balam  is rotating around a first barycenter in common with S2007 (3749) 1 (in catalog as "Balam-S2007"). This barycenter, in turn, rotates around the main barycenter, true center of the system, in common with S2002 (3749) 1.
So for SpaceEngine, is not Balam having satellites, but its parent barycenter having 2, and the main barycenter "Balam system" having 3 (S2002 + Baryc. Balam-S2007).
By this reasoning, S2002 it shouldn't show 2 moons at all, which could mean it's a bug indeed, but having the asteroid Balam showing none in info is consistent with SpaceEngine simulation.
With Litva the situation is the same.

I'm afraid I fail to see where it says S2002 is the largest, Balam and S2002 diameters seem to match data from Johnston's archive. Could you be more specific?

Permian Therapsid wrote:
Source of the post Trans-Neptunian 1998 WW31 is missing its moon.

There are many missing :) Right now I'm slowly going through main belt confirmed binaries from Johnson's Archive, then there are still tons of confirmed NEOs and TNOs that will have to be added to the script. Then there are more which are probable binaries, some of them are already in the catalog. Lot of work in spare time.

It's not so difficult to make a script in order to add a binary asteroid, it's just a bit tedious after a while. I'm using a spreadsheet to fill the data and to do conversions and calculations, but I'm having fun in searching around the net if the data are confirmed or there are fresh news regarding the object, like a name change, or if it's in SE catalog with one of the previous denominations, or precise mass determination, things like that.

Thanks to all of you checking the catalog, feel free to contribute with scripts if you feel like it.
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COMMUNITY ADDON - Double/Multiple Asteroids fixes for SE

13 Apr 2017 04:55

Mosfet, I just want to thank you for your hard work. Great job. Hope someone helps you soon with the massive amount of objects we still need in SE
 
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COMMUNITY ADDON - Double/Multiple Asteroids fixes for SE

13 Apr 2017 07:01

Mosfet wrote:
If I understand correctly, you are noticing that according data info regarding s2002 (3749) 1 we see it as having 2 moons, while Balam data shows none. Let's see to figure out a reason why it says 2 moons.

 Balam and Litva are both triple systems, where we have 3 objects and 2 relative barycenters.
Balam  is rotating around a first barycenter in common with S2007 (3749) 1 (in catalog as "Balam-S2007"). This barycenter, in turn, rotates around the main barycenter, true center of the system, in common with S2002 (3749) 1.
So for SpaceEngine, is not Balam having satellites, but its parent barycenter having 2, and the main barycenter "Balam system" having 3 (S2002 + Baryc. Balam-S2007).
By this reasoning, S2002 it shouldn't show 2 moons at all, which could mean it's a bug indeed, but having the asteroid Balam showing none in info is consistent with SpaceEngine simulation.
With Litva the situation is the same.



Space Engine seems to be fine with showing the number of moons for the largest object in the barycenter system. Take the multiple TNO Pluto for example. In this system SE shows the barycenter "Pluto-Charon" having 6 satellites and Pluto having 5. Also as another example, the binary asteroid Antiope is shown having 1 moon and barycenter "Antiope system" is shown with 2 satellites.

Mosfet wrote:
I'm afraid I fail to see where it says S2002 is the largest, Balam and S2002 diameters seem to match data from Johnston's archive. Could you be more specific?


I did just find out that multiple TNO system 1999 TC36 has the barycenter shown with the satellites but unlike Pluto-Charon or Antiope system, the number of moons are not shown in the data on the largest component. I think that may be because the largest object in the system is having wrong name in the barycenter's data.

In case of 1999 TC36, it says that a barycenter named "1999 TC36 A" is largest "object" in the barycenter named as "1999 TC36" so it gives the number of moons for this barycenter of 1999 TC36 A and not the largest object (named in SE as "1999 TC36 A2") unlike Pluto-Charon or Antiope system, where the number of moons is given for the largest object. In the Cases of Antiope system and Pluto-Charon the largest object in barycenter's data are given as "Antiope A" and "Pluto", and SE displays the number of moons for Antiope A and for Pluto.

In the case of "Balam system" and "Litva system" the data of the both barycenters tells that largest object is S2002 or S2012, instead of Balam or Litva. The sizes are correct in the game, just the data on barycenter's largest object is wrong. I think this may be the reason why the number of moons is shown for the wrong component. This is what I did mean when I was talking about S2002 being largest. The 1999 TC36 seems to have the same problem, the name of largest component is wrong on the data of the barycenter.  

Mosfet wrote:
Thanks to all of you checking the catalog, feel free to contribute with scripts if you feel like it.


You are welcome! I am happy to help reporting these issues as I would like to see this wonderful program without error, including this addon.
 
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COMMUNITY ADDON - Double/Multiple Asteroids fixes for SE

13 Apr 2017 09:05

Permian Therapsid wrote:
Source of the post I would like to see this wonderful program without error, including this addon.

Eh, (un)fortunately there's always measurement uncertainty ;)

Permian Therapsid wrote:
Source of the post In the case of "Balam system" and "Litva system" the data of the both barycenters tells that largest object is S2002 or S2012, instead of Balam or Litva. The sizes are correct in the game, just the data on barycenter's largest object is wrong

Ahh, now I see, in wiki orbital info. Yes, since barycenters in the script have no radius data (null), it's possible that if there's a second barycenter SpaceEngine picks for that value the bigger asteroid from the remaining, to the extent of ignoring a more massive object in the first barycenter.
Maybe SpaceEngineer knows better.

Grazie, FastFourierTransform, you're welcome.
Last edited by Mosfet on 14 Apr 2017 11:49, edited 1 time in total.
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COMMUNITY ADDON - Double/Multiple Asteroids fixes for SE

13 Apr 2017 13:25

Mosfet wrote:
Eh, (un)fortunately there's always measurement uncertainty ;)


I know this, of course. I was just trying to say we should try to make the errors as small as possible considering the available data on these objects.

Mosfet wrote:
Ahh, now I see, in wiki orbital info. Yes, since barycenters in the script have no radius data (null), it's possible that if there's a second barycenter SpaceEngine picks for that value the bigger asteroid from the remaining, to the extent of ignoring a more massive object in the first barycenter.
Maybe SpaceEngineer knows better.


So you do think the problem is that these systems (Balam, Litva and 1999 TC36) do have 2 barycenters instead of just one like Antiope and Pluto? And this might be why Litva, Balam and 1999 TC36 systems display the moons in a wrong way, while Pluto and Antiope display them correctly. I think that it would be good if you could ask SpaceEngineer about this problem.

 -                            -

Could I ask how the diameters of asteroids and other objects shown in the game are calculated? Is this equatorial diameter, mean diameter or what?
I did post a comment concerning incorrect and missing data on Solar System's minor planets, comets and moons in SpaceEngine on "General questions about SpaceEngine" thread. 

Some of them have obviously incorrect diameters but others seem to be close to values close to ones I have seen. This thread is obviously not the one to discuss this matter but it would be nice to know where the data came from and how it was implemented in SpaceEngine. Do you know did SpaceEngineer himself add the data on all the Solar System objects included without addons or did other people help him? Sorry if I ask this here, was just wondering the asteroid diameter calculation in the game engine as many asteroids are not very regular shaped.
  
 
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Permian Therapsid
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COMMUNITY ADDON - Double/Multiple Asteroids fixes for SE

13 Apr 2017 13:27

It would be nice if I could ask SpaceEngineer about this, he has done wonderful work creating this amazing program. 
 
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COMMUNITY ADDON - Double/Multiple Asteroids fixes for SE

13 Apr 2017 17:10

As far as I know, regarding real objects, radius of objects is specified by scripts like those you see in previous messages of this thread, with a specific syntax you can learn in the manual, under "creating a planet" section and elsewhere. It's good to check existing scripts as examples, or templates to play with.

The manual is quite exhaustive about how SpaceEngine works, but in general radius of asteroids is one of the key values to be used and usually not calculated but provided manually from various sources, such as NASA, JPL, Minor Center Database, Johnston's Archive... Of course discrepancies from sources are expected.

Actually SpaceEngine tries to calculate some needed values via algorithms if not provided, using known/plausible relations between magnitude, radius, family types...
I think most of wrong values you listed in the other thread are likely due to wrong inputs, sometimes wrong copy/paste, or wrong data conversion. Even star catalogs are filled with errors, so there's always something to do :D

Shapes are usually randomized by the program using procedural seeds, starting from a sphere of provided radius. If the object has a known irregular shape, I think usually mean radius is used, but sometimes if the results are not much good-looking, I think we can change things a bit to help the program. If that's the case, usually there's a comment in the corresponding value to inform the reader about it.
As a side note, SpaceEngine algorithms are making wonders but I believe SpaceEngineer is a perfectionist, so they are rightfully tweaked and tuned in every moment.

You can change the shape of an asteroid, right now in a limited way but it will change in future, by selecting the object and using the in-game editor (Shift-F2), then by saving the results in a script.

Unfortunately at the moment we can't have precise shapes of the many interesting asteroids we approached and imaged directly with probes in last decade or so. In time we'll have it.

I'm sure SpaceEngineer reads the threads quite often, so don't worry :)
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COMMUNITY ADDON - Double/Multiple Asteroids fixes for SE

14 Apr 2017 13:36

Mosfet wrote:
As far as I know, regarding real objects, radius of objects is specified by scripts like those you see in previous messages of this thread, with a specific syntax you can learn in the manual, under "creating a planet" section and elsewhere. It's good to check existing scripts as examples, or templates to play with.

The manual is quite exhaustive about how SpaceEngine works, but in general radius of asteroids is one of the key values to be used and usually not calculated but provided manually from various sources, such as NASA, JPL, Minor Center Database, Johnston's Archive... Of course discrepancies from sources are expected.

Actually SpaceEngine tries to calculate some needed values via algorithms if not provided, using known/plausible relations between magnitude, radius, family types...
I think most of wrong values you listed in the other thread are likely due to wrong inputs, sometimes wrong copy/paste, or wrong data conversion. Even star catalogs are filled with errors, so there's always something to do :D

Shapes are usually randomized by the program using procedural seeds, starting from a sphere of provided radius. If the object has a known irregular shape, I think usually mean radius is used, but sometimes if the results are not much good-looking, I think we can change things a bit to help the program. If that's the case, usually there's a comment in the corresponding value to inform the reader about it.
As a side note, SpaceEngine algorithms are making wonders but I believe SpaceEngineer is a perfectionist, so they are rightfully tweaked and tuned in every moment.

You can change the shape of an asteroid, right now in a limited way but it will change in future, by selecting the object and using the in-game editor (Shift-F2), then by saving the results in a script.

Unfortunately at the moment we can't have precise shapes of the many interesting asteroids we approached and imaged directly with probes in last decade or so. In time we'll have it.

I'm sure SpaceEngineer reads the threads quite often, so don't worry :)

Thanks for the informative comment, I just did discover these errors in various asteroids and TNO:s considering the values listed in JPL small body database and those in research papers for more recent estimates especially concerning TNO:s. Rotation periods seemed to be  generally too long for asteroids with known rotation periods in SE according to JPL database data.
I am hoping that in near future all those asteroids and TNO:s and their moons imaged close by spacecraft will have realistic shapes and textures included in SE. In the current version if I am not mistaken only Ceres, Vesta, Pluto and Charon have real textures used for them for closely imaged TNO:s and asteroids. 
 
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COMMUNITY ADDON - Double/Multiple Asteroids fixes for SE

14 Apr 2017 14:44

Gaspra, Ida, Dactyl, Lutetia, Annefrank, Mathilde, Steins, Braille, Toutatis, Eros and Pluto's small moons, all these have some close or relatively close observation data yet available, but Steins, Annefrank, Mathilde and Braille are not yet included in Space Engine, and the others lack realistic shape/and or textures. Am I correct on this observation? 
 
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COMMUNITY ADDON - Double/Multiple Asteroids fixes for SE

16 Apr 2017 02:37

Permian Therapsid wrote:
are not yet included in Space Engine, and the others lack realistic shape/and or textures. Am I correct on this observation?


You're right. Unless they're in SpaceEngine with previous known designations, some well known asteroid may not be yet in catalog.
As for a realistic shape of non spheroidal nature, as I previously said can't be done yet and obviously this affects the presence of related realistic textures.
Given your evident interest, I suggest you to try and correct some scripts to be placed in related threads.
You should find examples in the manual, play with an existing script and see what happens ;)
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COMMUNITY ADDON - Double/Multiple Asteroids fixes for SE

17 Apr 2017 09:04

Mosfet wrote:
Permian Therapsid wrote:
are not yet included in Space Engine, and the others lack realistic shape/and or textures. Am I correct on this observation?


You're right. Unless they're in SpaceEngine with previous known designations, some well known asteroid may not be yet in catalog.
As for a realistic shape of non spheroidal nature, as I previously said can't be done yet and obviously this affects the presence of related realistic textures.
Given your evident interest, I suggest you to try and correct some scripts to be placed in related threads.
You should find examples in the manual, play with an existing script and see what happens ;)

Ok, I will try to see what can be done, but if you who have been working with this addon for some time can not fix the Balam, Litva and 1999 TC36 system issues for example, how could I do it? I hope SpaceEngineer could do something to this soon if no one else can fix it.
 
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COMMUNITY ADDON - Double/Multiple Asteroids fixes for SE

17 Apr 2017 09:23

Well, the fix you are referring to, regarding multiple barycenters, could be valued, tested and applied to the source code of the program by the one and only programmer SpaceEngineer. If there's an easy fix, that is.
The best we users can do is check and correct data errors or propose new data entries for missing objects, that's the easy part :)
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Permian Therapsid
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COMMUNITY ADDON - Double/Multiple Asteroids fixes for SE

18 Apr 2017 23:26

Mosfet wrote:
Well, the fix you are referring to, regarding multiple barycenters, could be valued, tested and applied to the source code of the program by the one and only programmer SpaceEngineer. If there's an easy fix, that is.
The best we users can do is check and correct data errors or propose new data entries for missing objects, that's the easy part :)

True, but could you help me to tell how I can correct data errors? And what is the best thread to propose the new additions for the game?
 
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COMMUNITY ADDON - Double/Multiple Asteroids fixes for SE

19 Apr 2017 03:08

First you need to know how SpaceEngine works with data:  http://spaceengine.org/manual/making-ad ... roduction/
Read the manual, chapters "creating a star" and "creating a planet" indicate how to create .sc files and which parameters are needed.
Then you can extract all script files from a copy of your Catalogs0980.pak, and use a program like notepad++ to search for the object and the parameters you want to correct in one of the .sc script files. See what I did in COMMUNITY ADDON - Catalog Fixes for SE regarding one of the errors you signaled in another thread.

Maybe I should just say that the thread I linked above is the right one where you can point out errors you find, even if you don't know how to make a script to correct catalog data. Then most likely others will publish the needed script.
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COMMUNITY ADDON - Double/Multiple Asteroids fixes for SE

19 Apr 2017 07:25

Mosfet wrote:
First you need to know how SpaceEngine works with data:  http://spaceengine.org/manual/making-ad ... roduction/
Read the manual, chapters "creating a star" and "creating a planet" indicate how to create .sc files and which parameters are needed.
Then you can extract all script files from a copy of your Catalogs0980.pak, and use a program like notepad++ to search for the object and the parameters you want to correct in one of the .sc script files. See what I did in COMMUNITY ADDON - Catalog Fixes for SE regarding one of the errors you signaled in another thread.

Maybe I should just say that the thread I linked above is the right one where you can point out errors you find, even if you don't know how to make a script to correct catalog data. Then most likely others will publish the needed script.

Thanks I will post there and try to do fixing myself too. If I did understand correctly the manual does tell me how can I edit already existing objects in the Solar System without duplicating them. Take Chiron for an example. I should be able to add it an additional designation 95P Chiron and change its type from "asteroid" to "comet" since this is one of these objects that are classified as both minor planet and comet. And I should be able to add coma for Chiron. It's all names should be somewhat like this: Chiron / (2060) Chiron / 95P Chiron, and it should have a coma similar to Echeclus. 

Echeclus is classified as a comet in Space Engine and is missing minor planet designations but does seem to have a coma. Other dual classification objects that are both comet and minor planet are also missing designations. TNO/dwarf planet Pluto and several moons are also missing designations. I will post this soon in the other thread that you did link and stop posting here. Thanks again and I will read the manual carefully.

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