This project was done just for fun in two days. Ijust finsihed building my 3dr delta and calibrating it. After making a few prints i thought of doing some light painting by mounting a led on the head of the printer. The LED is connected to the servo pin 1 of the Ramps .
Marlin has a nice gcode extension ( M42 )where a pin on the arduino can be toggled on and off . I used this to toggle the Arduino pin D11 on and an off..
Next was the problem of creating custom g-code to do that.. I used grasshopper3d to make a custom script to create a simple G-code which creates lines every 3mm in the model.. The model doesn't even need to be water tight.
Also for simplicity i keep the feed rate constant at 3500 ( which is okay for the 3dr ) .. I even tried a dashed pattern but it is only visible in the fox model.