[Award Winner] Making Not so Random Coastlines in GIMP - alternative method

[RobA]

Gee Thanks! I just hope people find the techniques useful. I'd like to see what others end up doing with it!

-Rob A>

(p.s. what...no blush smiley?)

[pyrandon]

Wow--amazing. And although written for GIMP, I can so yoink this for Phosotshop as well. Great great great. Repped!

[ravells]

I tried this tutorial using Paintshop Pro last night and it worked like a charm. I'm going to try it again, but using different fills apart from noise to see if anything useful turns up. Thanks for the tut, Rob - very handy indeed.

Ravs

[RobA]

Good to see it can be applied in other software. (I used PSP back at version 4, but that was a while ago )

One other bit is to play with the curves dialog before blending the images. That will let you do things like the attached - and island ringed by a reef. (FYI - I just started with a blurry blob but used the curves adjustment to make the "ring" appear. I can grab the curves dialog if anyone wants, to show what I mean...)

-Rob A>

[RPMiller]

This is just rockin'!!

[mmmmmpig]

everything here can work in PS as well. Thanks for the method!

[OneSeventeen]

Care to elaborate, m5pig? I can't get interesting coast-lines using just Photoshop. I have done the texture-in-GIMP-then-import-to-PS thing, but that's cumbersome. I may post my results later, if I think of it and have time.


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[pyrandon]

(FYI - I just started with a blurry blob but used the curves adjustment to make the "ring" appear. I can grab the curves dialog if anyone wants, to show what I mean...)

Would you mind? That would be really helpful.

[RobA]

Sure - (and a picture or two being worth 1000 words)

Here I started with a straight gradient, then used the curves dialog to make it into a bunch of concentric rings. This just maps the input levels to the output levels. The height on the curved line represents output intensity. (I am working here on the "value" channel, which just means brightness.) I just followed the original steps to get the final result...

-Rob A>

[Faide]

For the total GIMP newbie (Like me) I've split this process up more clearly.

When I first looked at RobA's post I couldn't figure out most of the techniques, so I wrote this as I went along.
I can recomend the GIMP Help Index files as they helped me to do this from RobA's descriptions.

So here we go.

Open new file
Add a layer and colour it black (Ignore the background layer)
Use the lassoo (sp?) (and shift key for more than one) to define some blobs
Bucket fill white.
Unselect everything
Filters>Blur>Gaussian Blur
Set radii to 100ish and apply

Open a new layer below this one (Helps to make the top layer invisable)
Filter>Render>Clouds>Solid Noise (Crank the X and Y values to max)

Tools>Colour Tools>Levels
Slide the grey arrow in the centre to the left a little (about 1.9) and let go. The dark areas will become greyer.

Make the white blobs layer visable again and make it the active layer.
In the layers dialog box is a mode option with a drop down menu, click on the multiply option.
This should put the noise where the white bits were.
Then merge the layers together. (Layer>Merge Down)

Tools>Colour Tools>Threshold
Fiddling with the black and white arrows adjusts the outlines of the shapes.
Then press OK

Filters>Edge Detect>Edge
Press OK in the pop up box
This gives you a white outline on black background.

Layers>Colours>Invert

This should give you a black outline on a white background.

I hope this helps, I learned loads doing it.

Karl