Hi Jeff, unfortunately there isn't currently any way in MoI to generate a height-map rendering. MoI is focused on generating 3D model data right now.

Normally the software for milling machines accepts 3D data (like as an .stl file) and then calculates whatever type of information it needs for its particular procedures. The machine that you've got there is kind of unusual that it doesn't support any type of 3D data inputs. I noticed that they mention on their FAQ page that they want to add this to a future version of their software. You might contact them to see if they might have an early or beta version that supports this.

Otherwise, I suppose you could use a 3D rendering program like Blender, to create a height map by using a particular type of texturing that generates a color using distance. I'm afraid that I am not familiar enough with Blender's texturing to tell you the exact steps on how to do that though...

- Michael