Mathilde

[granthutchison]

With the partial data available, I've built an add-on for asteroid Mathilde, which you can download here:
http://www.lns.cornell.edu/~seb/celestia/hutchison/mathilde.html
Thanks to Selden for hosting the add-on; and to Jestr, who added imaginary data to complete the partial shape model.

Grant

[TERRIER]

Good work guys,

I'm just checking if this is a brand new asteroid for Celestia ?

[granthutchison]

I'm just checking if this is a brand new asteroid for Celestia ?

I'm not sure what you mean ... but as far as I know no-one else has built a model of Mathilde, at least using the limited real-world data available.

Grant

[Jeam Tag]

TERRIER: not, I do not think that a model, textured, with most precise of information on 253Mathilde exists, yes?

Grant: for my installation, I added an info line
InfoURL "http://seds.lpl.arizona.edu/nineplanets/nineplanets/mathilde.html
in the ssc file. Do you have a better link to summarize informations on this asteroid?
Other thing: 433Eros (that I had noted like addon in my repertory; model, textures and co-ordinates, from now is integrated in the main Celestia pack ? I ask that because my "Solar system" pages need to be reised, and to join together the making of asteroids observed by NEAR-Shoemaker that you realized appears relevant to me...
Forgot: it seems to me that your Mathilde may be small more smoothed little... but damn' t, with so few elements, and very so contrasted photographs (b&W) it is superb model, thank you Mr Hutchison.
Jeam

[granthutchison]

Grant: for my installation, I added an info line
InfoURL "http://seds.lpl.arizona.edu/nineplanets/nineplanets/mathilde.html
in the ssc file. Do you have a better link to summarize informations on this asteroid?

Jeam, there's no necessity for that line, since Celestia automatically looks for a nineplanets page when you click for Info on solar system bodies - so even without the InfoURL you're sent straight to the Mathilde page at http://www.nineplanets.org/mathilde.html, which looks to be identical to the mirror site you connect to.

Other thing: 433Eros (that I had noted like addon in my repertory; model, textures and co-ordinates, from now is integrated in the main Celestia pack ?

An Eros model and definition were always part of the Celestia distribution (at least since 1.2.5). A 1k version of my Eros texture has subsequently been added.

...it is superb model, thank you Mr Hutchison.

Not much credit to me. I just processed the shape-model numbers provided by Peter Thomas, and then passed the partial model to Jestr so that he could fill in the blank areas with some sort of terrain.

Grant

[Jeam Tag]

Jeam, there's no necessity for that line, since Celestia automatically looks for a nineplanets page (...)

I d'ont remember some small bodies are included, shame on me

An Eros model and definition were always part of the Celestia distribution (at least since 1.2.5). A 1k version of my Eros texture has subsequently been added.

Ok, this is what i resumed on my page... but i noticed a link for your hires tex -now not avaible: is it somewhere for download, or must i delete this reference?

Not much credit to me. I just processed the shape-model numbers provided by Peter Thomas, and then passed the partial model to Jestr so that he could fill in the blank areas with some sort of terrain.

I love Celestia, when talents collide Hope to add on line these addon note soon, thank again. Jeam

[granthutchison]

Jeam:
A high res model of Eros is available at http://www.lns.cornell.edu/~seb/celestia/hutchison/index-125.html#4.1, though it doesn't take a texture.
My 2k texture included with the low res model on Selden's website is now outdated - it has a 180-degree vertical mirror that was necessary for 1.2.5, but which will give wrong results if it's used now. Unless Selden is also happy to host a revised version of this texture for use in Celestia 1.3.x, you're probably best not to have a link to a hi-res Eros.

Grant

[Jeam Tag]

Jeam: A high res model of Eros is available at http://www.lns.cornell.edu/~seb/celestia/hutchison/index-125.html#4.1, though it doesn't take a texture. My 2k texture included with the low res model on Selden's website is now outdated - it has a 180-degree vertical mirror that was necessary for 1.2.5, but which will give wrong results if it's used now.

I spoke about these addons, indeed: I referred them in my catalogue, with a small image made with Celestia v125pre? (see the old page still on line...) Little by little, I try to correct the references noted for a few years. Well, I'll indicate that these addons (with good address) are right for former Celestia versions in a next update of my pages? Thanks, Jeam

[jestr]

Jeam,I have taken the above hires model of Eros and rotated it to work in Celestia 1.3.2pre1 made it to take a texture and inverted the 2k texture and tried to smooth out the seam (its still there though not so bad)
You can get it here
http://www.jestrstuff.0catch.com/index.html
All the best Jestr

[granthutchison]

Hey, Jestr - a little bit of text on your site giving credit for the original Eros work wouldn't go amiss!

Grant

[jestr]

OK its done.Sorry I didnt mean to offend anyone-Btw do you have anymore partial shape models I can play with ?Jestr

[granthutchison]

Btw do you have anymore partial shape models I can play with ?Jestr

Sorry, no - Mathilde's the only one I've run across.
BTW: the untextured Eros model has one advantage to it; if you've got space you might consider distributing it in the original, textureless version, too. That one doesn't have a seam in Celestia!

Grant

[jestr]

OK both versions are on that site-though its overloaded at the minute.Does this mean that the seam only appears when a texture is given to a model ?It would seem (groan) so.Jestr

[Cham]

Jestr,

I like your asteroids. But I have a criticism to do. They are too much alike. Too much squeezed ball like with bumps here and there. Can you do a more "typical" asteroid, with a strange complicated shape ? The Mathilde asteroid, for example, is absolutly great, but need to be smoothed in some places because we can easily see some vertices and surface triangles.

In the Mira add-on, there are three nice asteroids called X-1, X-2 and X-3. Unfortunately, they are rough and there are too much vertices and triangles apparent on them.

[jestr]

Cham,I can make any shape you want.The idea of my asteroids was to make a few generic ones for the differing type (class ?) of asteroids and to have different textures for the different types.It is need of an overhaul though so I am open to suggestions.I notice I have no P type asteroids.The vertices and triangles (faces) appear to be a Celestia problem as they are still there (so long as a texture is applied) no matter how much I smooth it (add more faces) along the Longitude 180 degrees line.No matter how I change the faces along this line you still get ugly seams.Check in wireframe mode -there can be a lot more faces along this line but it looks worse than other parts of the model with a lot less faces.Jestr

[Cham]

Ok about vertices.

Can you make a generic asteroid in the Mathilde style ? I mean, a big rocky object with large "craters" like holes. I'm thinking about a large metallic asteroid, all iron and nickel, with "spikes" like extrusions (but not too much spiked, because of vertices and triangles, and because of textures deformations).

What 3D modeling soft are you using ?

[jestr]

Send me a picture or pictures of the kind of asteroid you are looking for,you know you can use 'Mathilde' and put another texture on it,rotate it ? I want to update my asteroid models to take any texture but the thought of editing all the ssc's again puts me off a bit.Jestr

[Cham]

Yeah, I know what you mean

An asteroid picture ? I don't think I can find any.

What 3D modeling stuff are you using ?

[granthutchison]

If you want to watch Mathilde during the NEAR-Shoemaker flyby, I've added a two-day segment of the spacecraft's orbit around closest approach, available at http://www.lepp.cornell.edu/~seb/celestia/hutchison/mathilde.html#2
It's interesting to compare the approach and departure views in Celestia with those at http://photojournal.jpl.nasa.gov/catalog/PIA02479. Because 3ds objects in Celestia don't cast shadows on themselves, some of the shaded areas in real life appear illuminated in Celestia, but it's otherwise clear that I've got the geometry of the encounter correct, as well as the shape of the illuminated part of the asteroid.

Grant