I missed the Travelling Salesman function in tab "geometry" and section "others" with a cool icon. 

it helps in many things like manufacturing, logistics, and robotics to optimize the path of drillers.

and when tired to drill, it could be used for some cool art (Robert Bosch).

it also helps to express one's feeling....

here is 2D, but applicable to any surface

logic of the model

• import a picture
• surface sampling and stippling
• then Travelling Salesman

Big thanks DS RD!!