Asteroid Shape model collection

All about models for Celestia. How-to, programs, work in progress...
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trappistplanets
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Asteroid Shape model collection

Post #1by trappistplanets » 23.05.2021, 00:55

(repurposing this thread to something more useful than "Asteroid Apophis 2021 3d shape model" topic)

post any known asteroid meshes you have here

here are some that i know of

https://3d-asteroids.space/
and
https://www.thingiverse.com/search?q=asteroids&type=things&sort=relevant
Last edited by trappistplanets on 24.05.2021, 11:15, edited 2 times in total.

pedro_jg
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Post #2by pedro_jg » 23.05.2021, 17:24

LukeCEL once contacted Marina Brozović, the main author of the 2018 study where the updated Apophis shape models were presented. She sent one of those models, which Luke then uploaded to the Discord server. I have attached the .obj file here.
apophis.zip
(39.67 KiB) Downloaded 35 times

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Post #3by trappistplanets » 23.05.2021, 21:03

pedro_jg wrote:LukeCEL once contacted Marina Brozović, the main author of the 2018 study where the updated Apophis shape models were presented. She sent one of those models, which Luke then uploaded to the Discord server. I have attached the .obj file here.
POG, THANKS PEDRO!

Added after 31 minutes 19 seconds:
pedro_jg wrote:LukeCEL once contacted Marina Brozović, the main author of the 2018 study where the updated Apophis shape models were presented. She sent one of those models, which Luke then uploaded to the Discord server. I have attached the .obj file here.
converted it into a cmod
apophis cmod.zip
(356.08 KiB) Downloaded 48 times

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LukeCEL
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Post #4by LukeCEL » 24.05.2021, 02:01

I also have a model of the near-Earth asteroid (214869) 2007 PA8. This one I also got from emailing Marina Brozović, who was the lead author of this paper: "Goldstone radar evidence for short-axis mode non-principal-axis rotation of near-Earth asteroid (214869) 2007 PA8".

The format of the file is the same as OBJ, so just change the extension to OBJ.
Attachments
2007_pa8.wf.zip
(122.17 KiB) Downloaded 31 times

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Post #5by trappistplanets » 24.05.2021, 11:11

LukeCEL wrote:I also have a model of the near-Earth asteroid (214869) 2007 PA8. This one I also got from emailing Marina Brozović, who was the lead author of this paper: "Goldstone radar evidence for short-axis mode non-principal-axis rotation of near-Earth asteroid (214869) 2007 PA8".
thanks, i should rename this topic to asteroid meshes gallery

luke, do you have a model for this rock?
https://lightsinthedark.files.wordpress.com/2017/05/pia21597.gif?w=1000
i have been looking for a mesh for that rock but i was unsuccessful
Last edited by trappistplanets on 24.05.2021, 16:22, edited 1 time in total.

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Post #6by pedro_jg » 24.05.2021, 13:20

Shape models are sometimes hard to come by. I'll start by posting a few links here, and hope to add more over time.

While these sources are also used by the 3D Asteroid Catalogue, I'm listing them for completeness:
-Database of Asteroid Models from Inversion Techniques (DAMIT): https://astro.troja.mff.cuni.cz/projects/damit/
-Models derived from radar observations: https://echo.jpl.nasa.gov/asteroids/shapes/shapes.html
-Asteroids imaged by VLT/SPHERE: https://observations.lam.fr/astero/

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Post #7by trappistplanets » 24.05.2021, 13:38

sweet

is it possible for anyone to contact the maker of the models shown in this paper to send us the meshes
https://www.hou.usra.edu/meetings/lpsc2018/pdf/1053.pdf
there so NICE

Added after 20 minutes 5 seconds:
pedro_jg wrote:-Models derived from radar observations: https://echo.jpl.nasa.gov/asteroids/shapes/shapes.html
pedro_jg wrote:-Asteroids imaged by VLT/SPHERE: https://observations.lam.fr/astero/
i can't seem to download anything from those 2 sites, when i click on object name (and shape model file for tlt/sphere) it gives me gibborish

Added after 4 minutes 27 seconds:
nevermind

Added after 2 hours 18 minutes:
LukeCEL wrote:I also have a model of the near-Earth asteroid (214869) 2007 PA8. This one I also got from emailing Marina Brozović, who was the lead author of this paper: "Goldstone radar evidence for short-axis mode non-principal-axis rotation of near-Earth asteroid (214869) 2007 PA8".
do you have code for 2007 PA8?

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Post #8by SevenSpheres » 24.05.2021, 17:00

trappistplanets wrote:do you have code for 2007 PA8?

Here is a tutorial for making your own asteroid ssc files. Data for this specific asteroid can be found here.
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Post #9by trappistplanets » 24.05.2021, 22:39

SevenSpheres wrote:Here is a tutorial for making your own asteroid ssc files. Data for this specific asteroid can be found here.
okay

i made the rock

Code: Select all

"2007 PA8" "Sol"
{
   Class "asteroid"
   Mesh "2007pa8.cmod"
   Texture "asteroid.jpg"
   Radius 1.4

   EllipticalOrbit
   {
   Epoch           2459742.149762573496
   Period      4.80
   SemiMajorAxis   2.845848909322017   
   Eccentricity   0.6539302342368805   
   Inclination   1.994453383607742
   AscendingNode   141.3764304892597
   ArgOfPericenter 293.8678642170708
   MeanAnomaly   248.7999781566583
   }

   Albedo 0.4
   RotationPeriod 102.24
}


needed mesh
2007pa8 cmod.zip
(228.69 KiB) Downloaded 33 times

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Post #10by LukeCEL » 06.07.2021, 23:01

Hey everyone, sorry for the late reply. Here are some shape models of 624 Hektor from Josef Ďurech (via Franck Marchis whom I emailed).

Models A, B, and C are the convex lightcurve models, a contact binary model, and an separate binary model respectively.
Attachments
Hektor_models.zip
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Post #11by trappistplanets » 07.07.2021, 11:17

LukeCEL wrote:Models A, B, and C are the convex lightcurve models, a contact binary model, and an separate binary model respectively.
witch model will be the most accurate?

Added after 8 hours 48 minutes:
the halley model on 3d asteroid catalog is good, but it does not fully line up with the Vega images correctly so i fixed it a bit
it allines with giotto and vega images very nicely now

below is the download link for the cmod mesh
halley giotto-vega.zip
(1.69 MiB) Downloaded 13 times

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Post #12by LukeCEL » 07.07.2021, 23:22

Not sure which of the models is the most accurate, but I think Hektor is known to be a contact binary, in which case Model B would be the closest to reality.

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Post #13by trappistplanets » 08.07.2021, 10:57

LukeCEL wrote:Not sure which of the models is the most accurate, but I think Hektor is known to be a contact binary, in which case Model B would be the closest to reality.
on the model, where would center of mass be because its currently centured on lobe 2 and that is not the center of mass
it needs to be on the center of mass so it rotates correctly in celestia

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Post #14by LukeCEL » 10.07.2021, 09:14

trappistplanets wrote:it needs to be on the center of mass so it rotates correctly in celestia

I'm not sure where the actual center of mass is, but you could probably get it to rotate about whatever point you want by using the MeshCenter parameter.

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Post #15by trappistplanets » 10.07.2021, 12:24

LukeCEL wrote:I'm not sure where the actual center of mass is, but you could probably get it to rotate about whatever point you want by using the MeshCenter parameter.
can you send me the paper you saw that model in, there should be a figure comparing the shape model with radar and synthetic data
(ie, somthing like this https://ars.els-cdn.com/content/image/1-s2.0-S0019103513002285-gr1.jpg (its bennu)
if there is a figure like that, than i can figure out the real center of the object myself, because the fig also shows rotational axes

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Post #16by pedro_jg » 10.07.2021, 14:17

The source of the Hektor shape model is https://arxiv.org/abs/1402.7336

Now for some other shape models, another website from which they can be obtained is the "Interactive service for asteroid models" (ISAM). While most of these come from the DAMIT database (which is licensed as CC BY 4.0), there are a few unique ones in there. The license isn't entirely clear to me though; while there's a small CC BY-NC-ND 3.0 badge on the page (which would most likely disallow converting the models for Celestia), I'm not sure if this only applies to the renderings or to the mesh files as well. The English version of the license page would suggest that the only restriction is on commercial use, and the Polish version suggests something along the same lines.

The mesh files can be downloaded by selecting an asteroid from the dropdown menu on the left. A couple of tables should then appear, the bottom one having an "additional information" column with an [obj] link.

Among the "unique" models I was talking about, some of them are for the asteroids featured on the following publications:
Bartczak et al. (2014) "A new non-convex model of the binary asteroid 90 Antiope obtained with the SAGE modelling technique"
Marciniak et al. (2018) "Photometric survey, modelling, and scaling of long-period and low-amplitude asteroids"
Podlewska-Gaca et al. (2020) "Physical parameters of selected Gaia mass asteroids"

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Post #17by trappistplanets » 10.07.2021, 15:31

pedro_jg wrote:Now for some other shape models, another website from which they can be obtained is the "Interactive service for asteroid models" (ISAM). While most of these come from the DAMIT database (which is licensed as CC BY 4.0), there are a few unique ones in there. The license isn't entirely clear to me though; while there's a small CC BY-NC-ND 3.0 badge on the page (which would most likely disallow converting the models for Celestia), I'm not sure if this only applies to the renderings or to the mesh files as well. The English version of the license page would suggest that the only restriction is on commercial use, and the Polish version suggests something along the same lines.
"(which would most likely disallow converting the models for Celestia)"

#1 why do they have that as a copy right...
and #2 if that is the case than why post them here?


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