A) the approximate square footage of my target area.
B) a desired width of the target area.
C) an additional adjustment and movement system to aim the trebuchet.
Considering that our military budget runs consitently over 600 billion dollars I image that I can bombard my painting surface for, oh, $600,000...easily. That's .001% of the budget that we spend putting our military all over earth, which is 19 times higher than the next nearest budget for any country. Bombardment is something we do well! We should be able to have something at least recreational and entertaining that mimics the process, but instead leaves only latex and inert casing fragments to be swept up, if that is deemed necessary.
Back in World War One the German Army used a rail gun brought within range of Paris. If I recall correctly, within 26 miles of the city. And then they lobbed artillery upon it. I imagine they spent about a million bucks on that almost a hundred years ago. With so much invested on both machinery and military they pretty much ended up terrorizing the entire world with such a weapon.
These days farmers still play around with the idea of throwing pumpkins as far as they can.
These are the sketches that I came up with recently.
The last image is something I cobbled together from a kinetic sculpture I planned to go over a railroad.. This seems like the most reliable method to transport and adjust left and right how the trebuchet will throw my paint vehicle.