I didn't want to get off topic on Mark's thread, so here is the quick and dirty of the technique I used to produce the attached image...   Get your camera in position and save it.  Ray trace to suit your needs for clarity, save as a *.tif image (tif is lossless and allows layers in Photoshop).  Render and export a Line Drawing set as Extend 15, Squiggle 30, Amplitude 50 (play with the line setting so it looks "nervous" but not too nervous) using the same camera from ray trace.