1) You can use Filter>>Mathematical>>Scale with a single value to get the altitude you want. For example, if the input data is from 0 to 255 and you want it to go from 0 to 3000, scale by 11.76 (that is, by 3000/255). Another option would be to use Filter>>Mathematical>>Span and enter a low of 0 and a high of 3000; Wilbur will figure out the appropriate scaling and offset values to go from what's in the surface to what you requested.
2) Steps a through i in that tutorial are part of a loop. Pick the area that you want to affect and then start the loop, executing from a through j (j says "do a through i over again). The first time you perform step d as per the example, use 100; the second time you do step d, use 50; the third time you do step d, use 25. Keep chopping the value in half at each step. You're making a fractal altitude with these steps. Select>>From Terrain>>Height Range will select a range of heights from the terrain.
3) Wilbur will chop up that map nicely. Since you should be starting with a small (256 wide, maybe) image, so you don't even need to scale it up before you start. However, the stated process will pretty much keep your coastlines exactly as you specified them while generating the input.
Originally Posted by waldronate
1) You can use Filter>>Mathematical>>Scale with a single value to get the altitude you want. For example, if the input data is from 0 to 255 and you want it to go from 0 to 3000, scale by 11.76 (that is, by 3000/255). Another option would be to use Filter>>Mathematical>>Span and enter a low of 0 and a high of 3000; Wilbur will figure out the appropriate scaling and offset values to go from what's in the surface to what you requested.
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