Step 2: Getting the Map Ready for Cutting
You want to start with a high-resolution image that also has topographical information in it.
I chose my starting image (the first image for this step) because:
It has 9 layers, which is a good number of layers to have for this project.
It has distinct colors for every elevation, which makes it easy to turn the image into a vector file.
It's a map of Colorado. I live in Colorado. Colorado is an awesome place to live.
I found my topographical image by searching 'colorado topographical map' on Google Images and then I chose what I thought was the best result. Here is a zipped directory of all the image/vector files from this step . I wish I knew a better way to find topo maps for this project, but Google Images turned out to be the best way I have found so far.
1. Open up your map file in Photoshop
2. Crop your image to the area that you want to make your topographical map out of.
3. Erase/clean up any stray marks or lines on your image.
4. Using the magic wand tool (with 'contiguous' turned off), select one color elevation from the map
5. Cut and paste the selection onto its own layer.
6. Repeat steps 4 and 5 until each elevation has its own layer.
7. Fill in all holes in each layer so that every layer is made from solid shapes.
8. Save the map as a psd and then open it in Illustrator.
9. Select a layer, and convert it to a vector with Object > Live Trace > Tracing Options...
10. In the menu that pops up, set mode to 'Color' and also check 'Ignore White', then hit Trace.
11. Select the resulting object and finish it off with Object > Live Paint > Make
12. Repeat 9 through 11 for every layer.
13. Duplicate every layer.
14. Select the contents of half of the layers (so that you have a copy of each layer with no duplicates selected)
15. Change the fill color of the layers to blank, and the outline color to RGB red (which can be found in the RBG color swatch set)
16. Repeat steps 14 and 15 for the remaining layers, except change their outline color to RGB cyan. The red layers you have will be where the laser cutter will cut out your next layer, and the cyan layers tell the laser cutter where to etch out the outline of your next layer.
17. Make a layer with ~8mm diameter circles placed where you want your cities to be.
18. Now you should have a map that looks a lot like the one in the last picture for this step!