View Full Version : Test with galaxy tutorial

11-18-2009, 10:19 AM
I just saw the awesome galaxy tutorial posted here; http://www.cartographersguild.com/showthread.php?t=7069 and just had to try my hand with this one.

I've yet to position more bright stars in the galaxy, and I'd wan't to make the galaxy more "fleshed out". Has someone got any good tips?

(My other map is in limbo at the moment while I figure out how to make my mountains work)

11-18-2009, 06:21 PM
It looks like you used the Twirl filter with too high of a setting so I would relax that by half for something not so tightly spun. Just my opinion, mind you, but it looks like a coiled spring :) Looks pretty good otherwise.

11-18-2009, 07:50 PM
Or perhaps try the twirl filter at closer to 2/3 of the number you currently have, and then thicken it up. Duplicate the layer and gaussian blur the bottom one, for example.

I'm not sure which would get better results, so experiment! Release a little mad scientist.


11-19-2009, 03:13 AM
Real galaxies normally have separation between the arms of the spiral. The star density is pretty uniform here, and this galaxy is also oddly devoid of dark clouds.

11-19-2009, 05:17 AM
Yes I know that this doesn't look like a real galaxy. I've been trying different approaches in the tutorial, but the best way to really depict a galaxy seems to be drawing one in photoshop :/

The twirlfilter doesn't yield realistic results and it lacks depth. And in this one it is WAY to strong, even at decreased settings it twists exremely much. However it's fun anyway :)

The star density is as it is because I didn't bother to much with it for this test.

11-19-2009, 12:21 PM
It looks good, but as mentioned above it's a little to dense. Maybe it's a new type of galaxy ;)

You don't really need Photoshop for this tutorial, as I managed to get a deacent result with gimp! (though I don't remember how I did it...)

11-19-2009, 12:57 PM
Here are some real galaxies with the arms identified. Most spiral galaxies have only two arms, though some have as many as six to eight depending on your point of view. If you want to get a good feel for how galaxies look check out the GalaxyZoo's forum they have tousands of spiral galaxies in there. Also as has been mentioned, galaxies aren't generally as tightly wound as yours. Try only one or two windings.

11-19-2009, 12:58 PM
Some more galaxies.

11-19-2009, 05:26 PM
Never knew about the number of arms thing...nice info Wormy and nice pics. :)

11-19-2009, 07:15 PM
I've got this tutorial (http://blog.hexagonstar.com/galaxy-tutorial/) bookmarked for when I want to do spiral galaxies. Might be worth a try!

LOL! Ignore me, it's same one you used!

11-19-2009, 07:33 PM
Removed thread hijack..

11-19-2009, 08:52 PM
I too never knew that most galaxies had just a few arms until yesterday when i found this image (http://upload.wikimedia.org/wikipedia/commons/8/89/236084main_MilkyWay-full-annotated.jpg) and it gave me some inspiration to do some more experimenting.

I've gone back to the original image and reduced the twirl a little bit, increased the dark parts and butchered the rings, and now I think it's starting to look somewhat like a galaxy... these are really only the gas clouds at present.

11-20-2009, 09:37 AM
I think that image looks a lot more realistic. Give it some glow and I think you're on the right track.

This is just my personal opinion on the matter, but I think you'll find that the closer spiral galaxies (i.e. the ones we have larger pictures of) are generally going to have more arms and be more tightly wound. This is because the further away the galaxy is (in general) the younger it is. Some of the furthest galaxies in the GalaxyZoo have not even wound themselves one time, while the closer galaxies like Andromeda and Triangulum (and the Milky Way) are more tightly wound and look to have more arms. (I think the multiplication of the arms is actually just the nominal two arms being split apart by gravitational forces as they wind around the core.) So having more than two arms is okay, but if you look closely at the Milky Way images, the minor arms just seem to be fragments.

11-20-2009, 11:07 AM
Yes that's what I'm going for, two main arms and some arm fragments so I'm going to butcher the white areas even more.

With some star clusters added I think this will turn out quite good...

Thanks for the help!

11-20-2009, 04:33 PM
I like it. I'd put some clouds around the arms, but not so much that they fill up all of the space, give it some color, and plop down lots of stars. Nice job there.

11-21-2009, 06:49 AM
Another update. I've added the first cloud layer and the stars, added some colour as well. I think I'll add at least one or two cloud layers albeit less dense than this one. Next thing to do however is adding the core (the clouds at the center will be removed then...).

It feels like I'm on the right track at least :)

11-21-2009, 10:39 AM
I think it's looking good so far.

11-21-2009, 02:00 PM
Definitely on the right track.

11-21-2009, 06:07 PM
Thats looking really good now.

11-22-2009, 10:06 AM
I've finished adding dust, and I added some more stars to the arms and the Core. Next up is adding a "bar" to the core and placing some brighter stars.

11-22-2009, 10:52 AM
That is amazing. The arms look straight out of a Hubble photo.

11-23-2009, 11:43 AM
Thank you! It's a LOT of work on the other hand...

Another update... I've finished the galaxy and added 'longitude' and 'latitude' lines and started transforming it into a galactic map :)

I've shrunk the original map down by 50% to make 'zooming' possible. I've attached the image in original size as well.

11-23-2009, 07:28 PM
That's looking pretty delicious.

11-24-2009, 05:18 AM
Everything's great but the bar. It needs more substance. I'd suggest rotating it until it covers most of those core stars, and then filling stars in the significant gaps still present in the bar.

11-24-2009, 01:23 PM
Everything's great but the bar. It needs more substance. I'd suggest rotating it until it covers most of those core stars, and then filling stars in the significant gaps still present in the bar.

You're absolutely right, I've thought about it myself as well. In this version I've added quite a lot of stars to "flesh" it out.

I've also added another 'zoom' map and a close-up of the inner part of solar system and a planet...

11-24-2009, 01:51 PM
I think it needs more glow, but definitely a great improvement thus far.

Something to think about is that almost all galaxies have more than a billion stars in them. (Dwarf elliptical galaxies have closer to a billion and some of the more massive spiral ones have as many as a trillion stars.) The Milky Way has somewhere in the range of 100 to 400 billion stars. So if that map (3030x3030 pixels)was of the Milky Way each of the pixels on the map would have more than 10,000 to 40,000 stars in it. The dots you see on the images of the galaxies I posted are almost all in our own galaxy. (i.e. the stars that look like they are part of that galaxy are just really far away stars in our own galaxy in front of the distant galaxy.) However you will see some blue dots on most galaxies and those are the very rare blue giant and super giants that give off more light than 10,000 to 60,000 times that of our Sun. Also there are regions of star birth that give off a lot of light because of the densely packed stars in them. Blue giants represent 0.13% and blue super giants 0.00003% of all stars, so you would have about 130-520 million blue giants and 30-120 thousand blue super giants in that galaxy if it had about as many stars as the milky way.

So the glow I mention is the combined light of 10,000 to 40,000 stars in each pixel. They are more densely packed in the arms and grow more dense the closer you get to the core and are sometimes shrouded with gas. The blue stars you have dotting the arms right now easily represent those blue super giants but you need some glow to represent the couple thousand stars per pixel that exist even in the "dark" areas between the arms.

11-25-2009, 01:54 AM
Nice tutorial. I modified it a bit. Some changes were beneficial. Others... meh.
First change was between step 6 and 7. I used the Lasso Tool to select a couple of irregular areas at opposite corners of the crossed threads image. I feathered that selection(at I think about 60-80 pixel radius) and hit delete. This made a couple of void areas which added interest. They allowed for a suitably tight Twirl, while allowing for strongly distinct spiral. I think this idea was successful.

On the whole, I think my threads are too solid and distinct. Looks good from a distance, but up close it looks... odd. I need to do this again to work out where I went wrong. I think there are a few places where a much less smooth Spatter might have been in order.

One last touch was at the stage of adding the individual star lights. I got lazy and used Glitterato on a separate layer. The left example is of the Glitterato layer applied using Color Dodge blendmode, the right used a Soft Light blendmode. I'm leaning slightly in favor of Soft Light, I think.

I didn't get around to 3d effects yet.

What do you think so far?

11-25-2009, 01:24 PM
su_liam, the effort looks good though as you say it could certainly use some refinement.

A couple of suggestions:

1.) The dots you have around the galaxy (glitter effect?) should all be blue, you would not be able to detect the individual light of any star smaller than a blue giant or super giant from this range. The background color of the galaxy should be a bluish white with a little bit of reds and yellows thrown in sparingly. (The average color of a galaxy is skewed a bit bluish because even through there are fewer of the blue stars they give out a little more light than the smaller white, yellow, and red stars combined.) (Some galaxies appear somewhat reddish and I'm pretty sure this is due to redshifting rather than a accurate representation of the color, and conversely some galaxies appear very blue and I think this is due to blueshifting. Although the age of the galaxy and ho much star formation is ongoing will also effect the color of the galaxy.)

2.) The "dark" areas between the arms should have some glow. If you look at the image below you will note that the "dark" areas between the arms are still brighter than the intergalactic space around the galaxy.

11-27-2009, 03:07 PM
su_liam: For this map I barely used the first steps of the tutorial, and did some adjustments of my own, and since then I've totally deviated from it. Your galaxy looks quite nice but I think it has the same problems that my first try had: too tightly spun. But it certainly has potential!

wormspeaker: I've added some more dust and increased the glow of the stars. I know that it probably isn't enough but I will keep it that way for the moment and invoke artistic license :)

11-30-2009, 10:41 AM
It could use some more glow, sure, but it looks pretty good now.

11-30-2009, 10:16 PM
Added some more information to the map that's about it. I think I'll have this finished soon.

Steel General
12-01-2009, 07:43 AM
This is looking really nice. great job so far.

12-02-2009, 02:42 PM
Beautiful chart! One of the best I have seen here. I have to admit though that I am a bit fuzzy about what I am seeing with the Galactic Sector 2 box. Is it a cross section or something else?

12-03-2009, 05:08 AM
I have to admit though that I am a bit fuzzy about what I am seeing with the Galactic Sector 2 box. Is it a cross section or something else?

Yes it's supposed to be a cross section, even though it's only meant to be an indication of which part of the sector that is selected.

12-03-2009, 12:50 PM
This is probably the finished version of this map. Added a lot of information and tweaked the galaxy a bit.

12-03-2009, 01:35 PM
Man, that's all kinds of awesome. :)

Very well done.

12-03-2009, 02:43 PM
Wicked. Repped.

12-03-2009, 04:38 PM
Truly excellent work there. I still vote for more glow (that's just how I roll), but otherwise I think it is the best galaxy map I've seen bar none.

12-03-2009, 08:38 PM
Thanks all!

And yes it could use more glow, but I'm just unable to make it work :) I'm just not that good an artist yet.

Finished map thread. (http://www.cartographersguild.com/showthread.php?p=91692#post91692)

12-03-2009, 11:37 PM
Wow. Now that is simply magnificent. Beautiful work, Andartar!