[Award Winner] Creating Realistic Coastlines

[Mysterious Mapmaker XXIII]

The only advice that I can give you about which parts should be smoother and which crinklier is that (here on Earth, at least) it's entirely a product of natural forces such as tectonics, erosion, and sea level. How things appear on your map is further complicated by scale because very crinkly details in areas may disappear, while what would be relatively smooth areas locally might have significant detail when zoomed out.

Interesting. I guess now the question is, how do tectonics, erosion and sea level affect the smoothness of coasts, anyways?

[Mouse]

Awesome technique, OldGuy.

I used 2000 x 1000 base map, Gaussian blur 15, threshold of around 200. (all exaggerated from your numbers because the file was much larger)

Very *very* pleased with the result

Coastline Exercise.png

Thank you

[Tricks]

Works well in Gimp, too! Very nice technique. Duly repped!

Translated to gimp steps I used were:
* Filter | Noise | HSV Noise (Holdness 1, Hue 0, Sat 0, Value 255).
+ Edit | Fade (Darken Only)
* Filter | Blur |Gaussian Blur (2 or adjust to taste). *(1 will create very fine distressing and the larger the blur, the larger the effect)
* Colours | Threshold (adjust to taste). *(I found 160 is a good start, up to 185 for a lacier coastline)
* Fuzzy Select Tool (Threshold 0), click in black surrounding area.
* Ctrl-I to invert the selection
* Fill with White.

-Rob A>

Worked like a charm. I love that there are resources for GiMP on this site. As I am VERY NEW to the site, is there an area that is ONLY GiMP tips and tricks?
I have looked a couple times so far and have not found it yet.

[Mouse]

No separate areas Tricks, but that's because we are an inclusive lot. Most of us use more than one app to make a single map, so it wouldn't really make much sense to separate it all into different software departments.

Have you tried just putting 'GIMP' in the search engine and doing an advanced search in this forum only?

[Tricks]

No separate areas Tricks, but that's because we are an inclusive lot. Most of us use more than one app to make a single map, so it wouldn't really make much sense to separate it all into different software departments.

Have you tried just putting 'GIMP' in the search engine and doing an advanced search in this forum only?

LOL I'm barely able to work with GiMP. I can't imagine using more than one program to make a map.
Maybe I should just hire someone to bang me out a map. LOL

[Wildeman40]

thank you for the tutorial!

[FantasyFernweh]

This is a glorious tutorial - I hand draw maps, and always have a hard time creating organically (read: randomized) created variances. Mentally, I always fall into an orderly, even-spaced variation. I think I'll try something like this with a loose landmass drawing, then use a lightbox to trace the randomized variations! Thanks for the tips!

[FerryK]

SOmething I have to try out. Seen it a few times pop up now

[skaForge]

I developed my own method of creating realistic coastlines. I'm very pleased with how it turned out:

Old Guy Gaming - Creating Realistic Coastlines

Attachment 21565Attachment 21566

I'm ready to begin work on the actual map. My sketch shows the basic shape and dimensions that I want but the outline is too smooth. I wanted to rough it up to make it look more realistic. I looked through various tutorials but everything I tried distorted the original outline more than I wanted. Probably the result of my being new at this and not following the tutorials properly.

I kept at it though until I hit upon a process that I'm pretty happy with. This was done in Adobe Photoshop.

I started with my island in white and the surrounding area in black as shown in the first image.

* Filter | Noise | Add Noise (gaussian, monochromatic, set to 100).
* Filter | Blur |Gaussian Blur (set to 2).
* Image | Adjustments | Threshold (adjust to taste). *
* Select Magic Wand Tool, click in black surrounding area. (contiguous checked)
* Shift-Ctrl-I to invert the selection
* Fill with White. (contiguous unchecked)

That's all there is to it. Now I have the beginnings of my very first Photoshop map.

* -- Move the slider to the right. You want to eat away at your landmass. Don't worry about how the land looks at this step. We will fill it back in. We just want to roughen the edges. By creating "holes" everywhere, we are trying to let the outside creep in a little bit. If there are too many holes, the outside will never hit anything to stop it. You want just enough holes to let it creep in a little but then run into a boundary. You may have to undo and try different amounts a few times to get the effect you want. Once you've done it once, it will be much easier to do than it is to explain. : )

EDIT: There is an updated version of this tutorial at Old Guy Gaming.

This looks good; but when I followed the link to his website, I found the domain for sale! Still going to try this in Affinity.

[waldronate]

That's one of the problems with the internet. Like any living system, it ages and changes, with some parts dying off and disappearing while new parts appear. OldGuy hasn't been around for about 8 years now and the wayback machine looks like it stopped being able to archive his site back in 2019. https://web.archive.org/web/20191028...lines-to-a-map is the last capture of it.

I'm bumping up against the "old" category myself and soon I will die and my stuff will flywheel along for a little while after that and then it will all disappear forever. There is still a little hope in archive.org for some of the simpler stuff, but it will also disappear someday and take everything with it, just like the newsgroup archives did when Google decided it wasn't worth the not-very-much cost per year to keep that history around.