I have a map in JPG format that I want to turn into contour lines in CAD. I've been able to make it into a vector drawing in Illustrator (without really knowing what I'm doing with all the settings) but I think all I need is simple paths that follow these lines. The map is messy, and the lines on it just end up a big spaghetti object. Wondered if there's a fairly straightforward way to do this. I also have Rhino to work with.
nearly the same subject is discussed here, but the questioner had an overall problem from where to start. Tracing a raster image to simple paths with stroke but no fill
You should start in a photo editor such as Photoshop or GIMP and clean the things. You should make separate photos for the different detail classes. At least make (by the erasing the exessive parts and filling the holes if needed) separate images for
- altitude contours
- other data
If something has a different color, it is good to have it as a separate photo. All photos can be BW and also should be for easy tracing.
It's good to edit off all crap and discontinuencies from the lines and areas in the photo editor. Later it will be much more difficult.
You should trace the photos separately and combine them as different layers for easy refining and coloring. Put a couple of aiming crosses or corners into each photo in the same position and keep the ungrouped layers available just as assurance against moving something accidentally.
Texts you probably must recreate by writing them yourself in Illustrator. A detailed map vill have quite a bunch of layers to stay manageable.
Note: vectorizing a detailed large area map is a major task. It should be seriously thought if it would be easier to buy that data from the supplier of the map or alternatively "can we live with the rasterized map?" Or can we afford to outsource this job? There are companies that are specialized to vectorize images.
Rhino is 3D modeller. It has no job in pure 2D work. It will be a good starting tool for 2D illustrations of complex 3D objects assuming that creating the 3D model is no problem.
Do not forget: Maps are generally copyrighted - an exact copy can lead to lawsuits.