View Full Version : cratered, rocky moon

01-02-2010, 10:58 PM
Okay, so I've been attempting to create a moon image, with lots of impact craters on its surface, but I've been unable to create a result I'm happy with. I feel like I'm starting to get close, but I have a few issues that I've been unable to work around so far.

The majority of this moon was made by following Ascension's planet-making tutorial (http://www.cartographersguild.com/showthread.php?t=3388).

After rendering the clouds, I used the eye candy water drops filter to create a lot of circles, and use stylize->glowing edges to brighten the ridges before rendering the difference clouds. However, the water drops filter creates circles that are too large and too even, and I'm wondering if anyone here might have any suggestions on a method to use that doesn't involve the water drops filter.

I found a few tutorials on craters in various places, but they all seem to require a little bit of hand-drawing talent that I don't possess ;)

01-02-2010, 11:58 PM
It's not too bad at all really. I don't know of any filters (apart from Lunarcell by Flaming Pear) that will do it for you automatically. I'd go in with by hand with the smudge, blur, dodge, and burn tools and push things around a bit. Maybe even a little bit of hand touch-up with an irregular brush on low opacity. Barring that, check out Lunarcell. :)

01-03-2010, 12:16 AM
That's a really cool plugin Mearrin, thanks for the tip :)

01-03-2010, 01:22 AM
I'd probably take out the 300-pixel airbrush, increase the spacing to 200% or more, set some scatter and some size jitter, and then make brush strokes...the result will be various size black dots but since it's an airbrush the edges will fade so the centers are black and therefore deeper. Set that layer to multiply and adjust opacity then merge down.

01-03-2010, 02:46 AM
Ooh that's a fantastic idea Ascension :) I'll have to give that a shot tomorrow.

On a side note, here's what I was able to make by combining your tutorial with LunarCell:

01-03-2010, 05:28 AM
I have the impression that it is actually not a sphere but a circle; the texture should be more curved at the edges.

01-03-2010, 12:49 PM
I think the problem with the first one is that the craters are too perfectly spherical and unbroken. I could be mistaken, but if an impactor hits the surface at an angle, it will create a slightly elliptical crater, yes? Still mostly circular, but just slightly squashed.

Also, the craters lack depth; it looks like there's a tiny ridge at the edge of each, but that otherwise the surface is a perfect sphere. If you're working with a flat map-image and then mapping it to a sphere, maybe try throwing some of the mountain tricks in the tutorial section (Pasis, et al) onto the ridges. That'll help the height of the ridges.

If that doesn't fix the depth of the craters, you could also possibly run the spherize filter on individual craters one at a time, with a negative value (or the pinch filter, I believe, will do the same), to warp the texture into appearing more distant.

I like the work so far, though; you're giving me a lot of ideas. Nice one!


01-03-2010, 02:27 PM
Yeah my issue with the first one is that all the craters are unbroken. If you impacted the moon with random asteroids then even if the craters were circular then at the very least the liklyhood that each one drops and makes a crater in a previously uncratered area is very remote. At least if there was this many craters. Our moon has craters of all different sizes and some of the smaller ones are circular but the big ones are partial circles interrupted with more large craters. There is also age. Old craters tend to be flatter and more ragged and the new ones crisp and well defined. I don't know whether this would work but maybe add one crater crisp and sharp and then put a slight blur on then put the next one in at a completely random point even if it overlaps. Then blur slightly again and add another and keep going.

01-03-2010, 03:11 PM
Thanks for all the great suggestions :) Lots of different things to try out, hopefully I'll be able to get some versions out soon, of the 'not-crappy' variety :D

01-03-2010, 03:56 PM
In the shop I always figure no job is *really* a good one unless I have to get a new tool. In that vein, if a good cratered effect is Really Really important, consider getting Pro Fantasy's Fractal Terrains (http://www.profantasy.com/products/ft_features.asp). It'll do single impact craters or wholesale bombardments. Not that I've ever generated a world then mercilessly pummeled it from above, no. Well, not many.

If your cratered wasteland needs Truly Huge impacts, keep the size of the overall orb small, since I think the biggest crater it'll do is 1000 units (you can use miles or km as your default measurement system). That way the proportional size goes up. Though really if you want mares and plains, you'd do better to start with a low-roughness world and/or do some manual tweaking.

12-27-2010, 02:31 AM
Hurray for reviving long-dead threads! :) Turns out the addition of some free genetica textures and layer styles to Ascension's tut work wonders. And I suppose that having a better idea of what I'm actually doing helps too :P Thoughts and comments welcome as always!