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

[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.


117

[mmmmmpig]

The process I used is basically the same.

Create white object on black background
Gaussian Blur
Create new layer of black
Filter-> Render-> Clouds on the solid black layer
De-saturated the clouds (Levels, Curves, Variations, however)
Set the original Black and White image to Multiply
Flattened and Thresholded
Filer -> Stylize -> Find Edges

Here is my result






Now we will see if I can post multiple images...

Woo Hoo the post worked!

[OneSeventeen]

Thanks for posting, m5pig. I think I may have figured out what my big problem was: resolution. I was working on a 10x7 inch piece with 100 pixels per inch.

When i cranked the size up to 2550px x 2550px I had much better results. What kind of resolutions and sizes do people work at? Specifically, I'm aiming at printing to an 8.5x10 sheet of paper and not taking up the whole thing (just so I don't have to muck with printer margins, etc.)


117

[mmmmmpig]

I very rarely work at less than 300 dpi for anything I am doing, whether it be maps or digital painting. When I go to print or post on the web, that is when I down-sample. Just an FYI, to minimize downsampling artifacts, only resample at most by half at a time. If you have a 600 dpi image and you want to get it to 96 dpi, start by resampling to 300 dpi, then to 150 dpi, and finally to 96 dpi.

[su_liam]

I may have said this somewhere already. If so, excuse me, please.

I've made some interesting noise with good ridges and channels by running Filters>Render>Clouds then Filters>Render>Difference Clouds a few times. I used to hate the look of Difference Clouds, but it has grown on me. I suspect the ridgier noise would produce more peninsulas and fjords and suchlike. I like fjords. Call me Slartibartfast. Mostly I use third party noise generators, anyway. One I like is planet by Torben &Aelig;gidius Mogensen. To get heightfields suitable for import into PS, I created a special greyscale color scheme. There's also some thing in Java I mentioned in another thread.

[DarkOne]

RobA, I trying to follow your GIMP tutorial but failing miserable. What version of GIMP are you using and which noise, blur, etc filters are you using?

From all your examples this is an excellent method for creating coastlines.

EDIT
I found your first how to, which gives all the correct filter to use.

Only problem I have is when you add a mask to the layer I don't get the last option of selecting a channel, so I can select the Land mask. What could be the error? This is at the stage of creating sea contours. Which is also applicable to this how to using another method of multiple instead of overlay.

[RobA]

RobA, I trying to follow your GIMP tutorial but failing miserable. What version of GIMP are you using and which noise, blur, etc filters are you using?

From all your examples this is an excellent method for creating coastlines.

EDIT
I found your first how to, which gives all the correct filter to use.

Only problem I have is when you add a mask to the layer I don't get the last option of selecting a channel, so I can select the Land mask. What could be the error? This is at the stage of creating sea contours. Which is also applicable to this how to using another method of multiple instead of overlay.

Are you in the right topic? I don't recall setting up channels in this technique.... (did you watch the video?)

By "failing miserably", can you give more information/post a result? The main problem I have seen is blurring too little compared to the entire image size. For example, if you are starting with an image of 3000x3000, a 100 px blur won't provide much of a random coast, it will look pretty much like the original hand picked blob...

-Rob A>

[DarkOne]

Your first "How to" did solved my failing miserable. I also using 1 version older GIMP that you that is probably why I missing the option to choose Channel on the Add Layer Mask.

[Xeviat]

The process I used is basically the same.

Create white object on black background
Gaussian Blur
Create new layer of black
Filter-> Render-> Clouds on the solid black layer
De-saturated the clouds (Levels, Curves, Variations, however)
Set the original Black and White image to Multiply
Flattened and Thresholded
Filer -> Stylize -> Find Edges

I'm having trouble with the "Set the original black and white image to multiply" step. Is that through the blur tool or the blur filter? Thanks.

PS: I downloaded the tutorial video, but all I'm getting is audio.