This YouTube series has some great instruction for making:
Lake Map
City Map
Coastal Map
What I like is that he also tells you how to do your own.
With the Shop reopening on Saturday this seems a
good time to start one if ever you’ve harbored the desire.
Here is a new piece of software(web page) from the University of Kansas which gives you control of the location and specifics about the STL file you’d like to generate like resolution, max Z, etc. The STL is already closed and ready for import into laser, 3D printer or software like KiriMoto( http://grid.space ) for slicing/GCode/toolpath generation:
TouchTerrain: Easily Create 3D-Printable Terrain Models (version 3.x)
Oh heck, why stop with SD quality video …
Fine Finishing: 0.031" Ball … HD Video
Honestly? I think the 1/8" ball did a perfectly decent job
but the limit could have been in the model itself.
Perhaps there was no more detail to reveal.
Looks nice and I agree, there are probably some settings in the STL creation process which would affect final resolution. I didn’t play with it beyond generating an STL of Mt Soledad and then viewing in MeshLab.
Just curious, what is the change between a roughing cut and a finish cut? I assume it has to be settings in the software. Is it just a change in the bit and another pass?
it is up to the user but most all CAM software has it as another setting since most people want some measure of resolution better than the rough cut. So sometimes it’s a bit change which just changes the shape and doubles or triples the pass resolution( ie 3 passes of a round bit in the space of the rough cut square endmill ) and other times it’s even a much smaller diameter bit so that tight inside corners can be cut out.
CNC milling has a bit more complexity and user defined choices over laser gutting. But that’s what also makes it interesting and rewarding.
3D carving is done in two passes. The first, referred to as the Roughing Pass, uses a larger flat end mill to remove the bulk of the material while never cutting too close to the actual model. The second, referred to as the Finishing Pass, typically uses a smaller ball nose end mill and cuts right to the boundary of the model.
Another major difference? Bite size.
The roughing pass will typically step over up to 40% the diameter of the end mill with each pass. The finishing pass will typically step over 10-15% of a smaller diameter end mill. There are many more passes in the finishing process to produce a smooth finish largely free of scallops.
Here’s an overhead visual of the two passes:
Roughing:
Finishing:
A new description … I like it! 
Said like someone who has taught the topic, great pics too! 
