PDA

View Full Version : Making Mountains in GIMP



RobA
06-01-2007, 01:10 PM
I saw this post by Jurgen (http://www.enworld.org/showpost.php?p=3559908&postcount=72) (at EN World) on making mountains in GIMP and figured I share a technique I worked out.

Hope the images all end up in the right order...


Make a shaky selection around the whole mountain. Keep the outline really ragged, not smooth:
Set colours for the base and peak of the mountain. fill the selection with a shaped angular gradient:
Duplicate that layer as a new layer and greyscale it:
Now stretch the contrast from black to white:
Apply a gaussian blur:
then apply a Filters->Noise->Spread to break it up:
Hide the B&W layer, and apply it as a bump map to the original coloured one:
Using a grungy brush and the colour of the mountain base, paint around the mountain (using the "below" brush setting)


9. and 10. Using Jurgen's grass and desert textures as backgrounds.

That's it... Hope it was helpful!

-Rob A>

Jürgen Hubert
06-01-2007, 04:56 PM
Very nice effect! I think I'll use this in the future...

keithcurtis
06-10-2007, 06:33 PM
I'm sorry, I had to vote no. I've seen similar techniques used on many different maps and none of them look convincing. That is, they don't seem to match real-world mountain forms. I'd like to use this technique, and have experimented with a lot of variations on it, but never been satisfied.

RobA
06-11-2007, 09:49 AM
I'm sorry, I had to vote no. I've seen similar techniques used on many different maps and none of them look convincing. That is, they don't seem to match real-world mountain forms. I'd like to use this technique, and have experimented with a lot of variations on it, but never been satisfied.

I agree it is not realistic. I present it as a cross between purely symbolic and aerial-photo realistic. Any primers or pointers to "the idiots guide to mountain shapes"? (hehe)

Though I must say, one could probably find a mountain anywhere in the world to match the most unlikely, unrealistic, un-mountainish shapes......

http://maps.google.com/maps?f=q&hl=en&q=50%C2%B0+0%2738.20%22N+110%C2%B0+6%2748.32%22W&ie=UTF8&z=17&ll=50.010538,-110.113585&spn=0.004895,0.009978&t=h&om=1

-Rob A>

heruca
06-11-2007, 10:47 AM
Cool link, RobA. :lol:

RPMiller
06-11-2007, 12:40 PM
That's crazy! Is that a natural occurring formation?

RobA
06-11-2007, 02:40 PM
That's crazy! Is that a natural occurring formation?

Yep-

Here is a bit more on it at CBC Radio:
http://www.cbc.ca/asithappens/features/2006/alberta_rock_sculpture_20061026.html

It includes a 1951 aerial photo (no road or well at that time) and a 3d model. I do stand corrected though, as it is a valley, not a mountain :)

-Rob A>

RobA
05-16-2008, 02:48 PM
Sorry for the crosspost.

I made a video tutorial (as they are all the rage) of this thread as it was recently resurrected. It creeped to almost 12 minutes (I tend to babble).

I recorded the screen in 1024x768 and scaled the video to 640x480 off line.

It is currently hosted at showmedo at 640x480 (though I think will host up to 800x600:
http://showmedo.com/videos/video?name=2620000&fromSeriesID=262

-Rob A>

Robber Baron
05-17-2008, 05:52 PM
Excellent tutorial! Thanks!

Normski
05-18-2008, 02:54 PM
Sorry, but I voted no - not because I couldn't find it of use, but becasue there were no explanations to the steps. It'd be good if you knew what was going on, but to a GIMP noob - sorry I couldn't follow it all,

Take Care,

Norm



Rob,

Three things Amigo,

Firstly - it's good to another Cardinal Fang Devotee :D

Secondly - Excellent tutorial, simple and easy to follow, I will be using this in future

Finally - This process, and all the others I have seem seem to produce a mountain range with the peaks in the middle, which is good enough. But what about escarpment ranges - where for example one tectonic plate, or similar, subducts another, raising the top plate gradually on one side with a steep fall-off on the other where the subdudtion occurs. The prime examples I can think of for this are the Rockies and Andes.

Basically - what I'm asking is how can we reproduce a non central range of peaks within a range? I'm not explaining this too well am I :(

Take Care

Norm

RobA
05-20-2008, 04:53 PM
Normski-

That type of range is even simpler. Just add some noise to a simple linear gradient, then play with the levels and curves.

Here is a simple escarpment heightfield on an oval:
3729

And here is a quick render in POV:
3730

From above (gimp alone):
3731

-Rob A>

Karro
05-27-2008, 12:26 PM
I saw this post by Jurgen (http://www.enworld.org/showpost.php?p=3559908&postcount=72) (at EN World) on making mountains in GIMP and figured I share a technique I worked out.

Hope the images all end up in the right order...




cont...


cont...


cont...


Here it is using Jurgen's grass and desert textures as backgrounds.

That's it... Hope it was helpful!

-Rob A>

I like the effect, better than that on the regional map tutorial you give. However, this is not as well explained, and I haven't had the opportunity to view the video as yet.

I gather that you draw an outline, and do some kind of color gradient, but I get lost a little later on, and I'm not positive what the b/w layer is for (maybe for generating the bumpmap that roughs it up?). How do you turn the initial color gradient into the mountains?

RobA
05-28-2008, 02:49 AM
I like the effect, better than that on the regional map tutorial you give. However, this is not as well explained, and I haven't had the opportunity to view the video as yet.

I gather that you draw an outline, and do some kind of color gradient, but I get lost a little later on, and I'm not positive what the b/w layer is for (maybe for generating the bumpmap that roughs it up?). How do you turn the initial color gradient into the mountains?

Went back and added some text for you, Karro.

HTH

-Rob A>

Karro
05-28-2008, 11:19 AM
Went back and added some text for you, Karro.

HTH

-Rob A>

Thanks! You've got a well-deserved reputation around here!

What does HTH mean?

ravells
05-28-2008, 11:29 AM
'Hope This Helps' - I think!

Karro
05-28-2008, 11:55 AM
'Hope This Helps' - I think!

Thanks. In all my time of sporadic forum-reading, I don't think I've ever seen that one.

EDIT:

Well, I tried to try the technique today, but I don't know what I'm doing wrong, and it won't work. Specifically, I can't make the Gradient Fill work. I can get a shaky-looking lasso selection that looks like it would make good mountains, I can pick mountainy foreground and background color. I can select the gradient tool and change the settings. But when I click in the selection, nothing happens. What am I doing wrong?

RobA
05-29-2008, 01:45 AM
Thanks. In all my time of sporadic forum-reading, I don't think I've ever seen that one.

EDIT:

Well, I tried to try the technique today, but I don't know what I'm doing wrong, and it won't work. Specifically, I can't make the Gradient Fill work. I can get a shaky-looking lasso selection that looks like it would make good mountains, I can pick mountainy foreground and background color. I can select the gradient tool and change the settings. But when I click in the selection, nothing happens. What am I doing wrong?

Did you watch the video? That should make it real clear and might point out what I am doing but not explaining :)

-Rob A>

Karro
05-29-2008, 01:56 AM
Did you watch the video? That should make it real clear and might point out what I am doing but not explaining :)

-Rob A>

Yeah, I watched it earlier, but when I went to try the technique, I didn't have 'net access, and I couldn't remember what I was doing wrong.

Then... suddenly, sitting here trying again, I remembered!

I can't just CLICK and have the gradient fill in. I have to CLICK and DRAG. I'm not sure if the amount of drag changes the nature of the gradient or not... about to test that now.

Thanks again!

EDIT: it looks like the length and direction of the drag has no discernible effect on the appearance of the gradient.

ravells
05-29-2008, 07:56 PM
Rob, for the life of me, I can't get that initial angular gradient fill you acheived. I'm not using Gimp, but photoshop and it's angular gradient gets me a result like this:

waldronate
05-30-2008, 01:23 AM
What Photoshop calls an angular gradient is exactly that: a gradient where the intensity represents the angle around the center point. It's basically the other half of the 2D polar coordinate representation (radial gradient is the first).

What GIMP is calling an "angular gradient" is what image processing folks would call an EDM (Euclidean distance metric) filter. It returns the distance from the edge of the shape.

There are plugins for Photoshop that will do what GIMP does, but the ones that I could find all seem to be part of expensive image processing plugin suites.

Wilbur will do this sort of thing (draw your selection, then use Select>>Modify>>Distance to calculate the gradient and Select>>Save Selection to save it as an image), but if you're going to involve an external tool you might as well just use GIMP.

ravells
05-30-2008, 06:07 AM
Thanks a million Waldronate. This is an incredibly useful tool. I tried to replicate it using Drawplus (a Xara type vector drawing proggie) and posted a request on their BB, but no dice so far except for an approximate fix by making a smaller contour of the object and then feathering the result.

RobA
05-30-2008, 11:32 AM
Yep. Like Waldronate says.

In Gimp, what photoshop calls angular is called COnical (and there are two.. your example would be asymmetrical. There si also symmetrical, which uses the gradient over 180 degrees and its mirror on the other half).

I was clear in one or two places, then started to shorthand. The fill for the mountains was "Shaped (Angular)" There is also "Shaped (Spherical)" and "Shaped (Dimpled)". ALl three of these have the gradient painted perpendicular to the selection outline.

A way that mmight work to manually do it in PS (at least in greyscale) would be to determine the maximum distance across the selection (perpendicular) call it D. Start with a black background, set paint to white with an opacity of 1.

Shrink the selection by (D/255) and fill the selection... repeat until no selection left....

Try it as an action....
-Rob A>

su_liam
05-30-2008, 12:13 PM
Nice. Very useful now. I've been playing with a little java app that does the distance filter thing. I'll rep you if it lets me. :)

edit:
Yay. It let me.

I'd move over to gimp altogether except for three things:
a)8-bit. I work a lot with 16-bit greyscale. I'd rather have double-precision float, but hey, reality.
b)Pen support. I can use my pen and tablet with gimp, but I can't get pressure sensitivity to work. This may be an issue with Apple's implementation of X11, but that's what I have...
c)Photoshop's more sophisticated brush attributes.
d)I know enough about Photoshop to make it dance. Learning curve is an issue.
e)Large-window greyscale erode and dilate. Only works on selections and they call it Grow and Shrink or some such, but a radius 3 Shrink is the same as a 7x7 dilate. Gimp only has 3x3 erode and dilate filters. Prettier, ultimately, but slower.

Hmm... I guess that works out to five.

RobA
05-30-2008, 11:11 PM
And gimp also has:

Mathmap (http://www.complang.tuwien.ac.at/schani/mathmap/)and Gluas (http://pippin.gimp.org/plug-ins/gluas/) to write your own (albeit slow running) filters!

-Rob A>

Steel General
06-20-2008, 01:17 PM
Where does one find the "Grungy Brush"?

RobA
06-20-2008, 01:39 PM
Where does one find the "Grungy Brush"?

Try DeviantArt (http://search.deviantart.com/?section=browse&qh=boost%3Apopular+age_sigma%3A24h+age_scale%3A5&q=grunge+brush) (link is to grunge brush search results.

-Rob A>

Ascension
06-20-2008, 04:52 PM
Crikey! 4,500+ grunge brushes....I only use about a dozen total. Guess it's time to expand my toolbox.

RobA
06-20-2008, 07:56 PM
Just can't have enough grunge :P

-Rob A>

bryguy
07-30-2008, 07:02 PM
Hey sorry for bumping this, but I have some questions for how you do some of the things....


oh and I found this while searching through the tutorials for how to make mountains, and so far this is most like the type i need to create.


so basically, I keep getting as far as the part where I need to greyscale the copy of the mountain for bump mapping it. Each time I try to greyscale the layer, it keeps happening to the entire image! and then, how do I stretch the contrast from black to white as you said I need to? and what about the "grunge" brush, which brush is it, or how do i get one?

nolgroth
07-31-2008, 07:17 AM
@bryguy
Are you using layers? Usually when you are working on a specific layer, it doesn't change the whole image. And if you still have the mountain range selected, it should just apply any changes to the selection anyways. Weird.

RobA
07-31-2008, 10:24 AM
@bryguy-

Don't use image->mode->grayscale

Use colours->desaturate

Then use colours->auto->stretch contrast (you might have to apply a small 1-2 px blur at that point if the histogram has too many gaps and looks like a comb) otherwise you will see banding when you bump map.

And re:grunge brush... I can't remember how it fit into this conversation :( Sorry :P

-Rob A>

bryguy
07-31-2008, 06:27 PM
ok thanks :)


lol and i just asked about the grunge brush cause i saw someone mention it...


edit:
@bryguy
Are you using layers? Usually when you are working on a specific layer, it doesn't change the whole image. And if you still have the mountain range selected, it should just apply any changes to the selection anyways. Weird.

yea im using layers, and i had it selected, but apparently i was doing the wrong thing

nolgroth
07-31-2008, 07:32 PM
And now you see why RobA is the resident guru. I never considered you were changing the image to Greyscale. :oops:

fantomx11
04-16-2014, 09:54 AM
Sorry for the necro, but I just wanted to add that this worked great. To get slightly more aesthetically pleasing results, I skipped the blur step and ran the smudge tool back and forth along each side of the ridge, and then along the ridge itself before doing the bump map.