automated crosshatching definition

There was a request for the basic definition I used to make this image.

Process:

Choose an image, and live trace it in illustrator. Expand the live trace, and save the illustrator file. Export the live trace as a jpg or other bitmap format. 

In Rhino, import the image with the PictureFrame command. Then import the illustrator file and scale the curves to the PictureFrame. Open the GH definition, and load in the illustrator live trace curves and the PictureFrame surface. Set the image source of the Image Mapper component to be the exported jpg of the live trace. Finally, specify your hatch angle (or angles) and activate the Bake toggle. 

hatch_by_density.ghx