[Award Winner] Technique for adding coastal detail as you zoom in.
I have been playing with a few techniques in GIMP (applicable to any raster program) to allow me to zoom in and "refractalize" a coastline without significantly changing the shape...
This technique is designed to work with a coastal outline (white land on black water) and will not directly translate to working with heightfields....
Steps:
1) Make a rectangular selection of the desired area, and copy it to a new image.
2) Enlarge the new image to the desired size
3) Blur it enough to get rid of the jaggies, but still maintaining some detail. I sued ~20 px in the examples. The bigger the blur, the more randomization will occur, and the less "true" the new coastline will be.
3) Create a new layer on top and set its mode to burn
4) Render clouds using the max detail and check turbulent. (I don't know what the photoshop equivalent of this is).
5) Invert (optional). Depends how it looks :)
6) repeat 4 and optionally 5 with different seeds until you get one you like. some just seem to work better than others. I kept a copy of the starting image open for reference to try and ensure coarse features were maintained.
7) Flatten the image (or just merge down the clouds layer).
8) Threshold with black at 1 or very low, again, maximizing detail while keeping the shape close to the original.
Here is a set of examples, with each showing the next one's selection. I started with a nice spherical mapped noise layer:
world_d.png
zoom1_d.png
zoom2_d.png
zoom3.png
-Rob A>
Last edited by RobA; 01-21-2008 at 06:39 PM.
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I would start by using Flexify to center the projection on the area of interest. For most useful projections(maybe all, I don't know), distortion is minimal near the center of the map. You could then build a collection of USGS-like 'topo' maps of your planet. Cool.
This is a great tip Rob! I'm going to need it as I move forward. Thank you, and I when I can, I'll rep you for this.
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It's really clever! Fractalisation on demand!
Now where was this when I was having to repeatedly zoom in on my map...? *sigh*
Bumpity bump! How can I use this in Photoshop? I don't have a turbulent option nor can I find Threshold.
Threshold is under Image-->Adjustments-->Threshold...
As for turbulent PS doesn't have an option. You'll just have to keep rendering clouds until you see something you like.
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What I do if I want to zoom in on an area for a larger map is I make the main landmass white and put it onto a black layer. Then filter > pixelate somewhere between 3 and 12 (this puts a bunch of white, gray, and black jaggie shapes in where the white and black meet). Then Image > adjustments > brightness/contrast and turn the contrast up all the way to remove the gray. Now you have a black sea and white newly jagged landmass.
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Just played around in PS with this... Created an action for it too.... Its pretty much the same steps as Rob said...
>copy, create new, paste, increase image size.
>Gaussin Blur 2.0 pix
>New layer set to color burn
>Filter>Render>Clouds. Filter>Render>Difference Clouds.
>Threshholds
>Lather>Rinse>Repeat
When we try this we always seem to get stuff like this:
http://www.novatainia.org/user_files...ractalnova.png
burning the clouds layers down doesn't appear to be working...
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