Celestia Forums

Heres a simple but quite effective model I've made for two galaxies -NGC 2207 & IC 2163 colliding.I just used the Sb model for both as this is what they looked like in the Hubble pic -Correct me if I'm wrong.Here's a picture

If you want to download it it is called NGC2207_IC2163.zip
You can get it here,just unzip it in your 'extras' folder
http://www.geocities.com/jestrjestr/extras
or from my FTP site
ftp://celestia:addons@81.111.74.239
Enjoy it.Cheers Jestr

And nobody greets you ?

It's by far the best galaxy addon I've ever seen, and believe me, I've downloaded all the addons you can find somewhere...

Congratulation, it's the FIRST time I really enjoy browsing a galaxy.

Marvelous, and thanks

Wow! I was really surprised by their 3D looks in Celestia! A suggestion/question though: would it be difficult to change the model to let the galaxies collide under a slight angle? I think it would improve the realism and beauty even further!

I think these two are actually colliding head on but there are definitely cases of other galaxies hitting all over the place.The model I made isnt much more than a figure of eight billboard,raised a little at the two centres of galaxies.I've added this on top of the standard Sb galaxy model used when 'Celestia' draws any spiral galaxy (obviously twice in this case).It would be quite easy for me to make any similar billboard and ones at different angles,but I'm not sure I know enough about positioning galaxies in Dsc files to match the angles.Do you have any collisions in mind ? (including a nice picture).Cheers Jestr

My opinion isn't just about the colliding galaxy, but actually about all the galaxies you made...

If I knew a little bit more about Celestia, and specially about 3D usage, I'll make it myself, but...

If you explain me how to do, I'll try to redesign all galaxies addon I own to use your new way.

Hi Jestr,

I found some details about their relative positions on apod (http://antwrp.gsfc.nasa.gov/apod/ap991109.html):
"... the smaller galaxy is swinging around counter-clockwise, and is now slightly behind the larger galaxy...". I think that one can guess the orientation of a galaxy quite well by assuming spiral galaxies are circular. Anyway, this way of modelling galaxies is beautiful enough for single galaxies!

added 3 sec later: you can see an arm of the bigger galaxy in front of the smaller one. It shows as a dark band just left of the smaller galaxy's core.

Psykotik, if you check the 'NGC 2207 and IC 2163.dsc' you will see that I have specified both the separate galaxies as sb Galaxy which draws the standard Sb spiral galaxy models in the standard 'Celestia' download.Then I have also specified 'NGC 2207' as a Nebula in a position halfway between the two Galaxies,this is the command that draws the 3DS billboard.I think if you try this with other nebula/galaxy addons you will find that the orientation of the 3DS models are out of line with the Galaxy models.There may be a way to correct this by entering an Orientation command line in the Dsc for the 3DS model but it is difficult to get it right-I usually change the orientation of my models in 3DS Max to get them to line up.
If you want to try it with single galaxies I suggest the billboard model I've used in my 'NGC 4414' addon but you will have to edit the 3DS file to point to the texture of the galaxy you wish to display and the orientation may have to be changed.Cheers Jestr

truly amazing stuff, would like to see more galaxies in celestia other than the blobs!

OK ,here's another collision (at a slight angle this time-Buzz)

If you want it get it here
http://www.geocities.com/jestrjestr/extras/
or here
ftp://celestia:addons@81.111.74.239
its called 'M51_NGC5195.zip' just unzip to your extras folder.
Can anyone tell me what the difference between the different galaxy models used by 'Celestia' is ? I've looked at Sb,Sc,SBb,SBc, and they all look the same.Is there any info anywhere about writing Dsc files ?
Hope you like the addon anyhow,cheers Jestr

Wow! I was expecting a plain billboard, but the way this is done makes it look really good... I've downloaded both.

I just got round to plugging these new nebulas in
and they look great, thank you jestr.

good work on the models too.

Very nice Jestr!

I downloaded the first galaxy zip folder,but when I went to open it the computer said it was Invalid or corrupted. I also tried downloading it again but no luck. I'm afraid i'm not very skilled with computers so I don't know how to fix it myself ;please help.

There is no doubt about your problem : the file has not been entirely downloaded, download it again.

It would be easier to download it by ftp (file transfer protocol) but since you don't knew much about computers, I don't want to scare you

Try only on the jest http site, at http://www.geocities.com/jestrjestr/extras/
and don't be astonished if you got a message about exceding his account, these geocities pages tend to be very stingy.

Thanks for the help these things look great. I know what you mean, one of my friends has a GeoCites account and he is always complaining about his data transfer.