Seeking help with an art project

Hi all,
I am new to the world of lasers so bear with me...

What I am seeking is the ability to project the outline of a square onto a night time streetscape (not completely dark - still lit by streetlamps)

I have seen on the web various "dotted square" caps like this: LPG5 - JOY LENS FOR LASER POINTER "dotted square" - Electronic Direct.be
Ideally however, I would like to project a non-dotted square. Do such lens caps exist?

Also, I would like to be able to control the size of the square projected, At its largest, the square's edges will be, say, 10m.

Given that this will be taking place in a public space, I'm obviously keen to avoid anything that has the potential to hurt the eyes etc.

Any suggestions as to the appropriate hardware would be much appreciated.

Cheers,
Cornelius

Only thing that came to my mind is laser scanner. It can project various shapes.

I think a scanning system would be the only way to get a solid square outline. The 'shape' lenses are really just specialized diffraction gratings, which break the beam up into many points. Circles are relatively easy and cheap to project. A quare would be more of a challenge to do on the cheap though, since it would require enough equipment to actually accurately control a pair of galvos. Such a setup would be a few hundred dollars at minimum to put together if you did most of the design and construction work on it yourself.

Great, thanks for the tips. "Laser scanner" turns up quite a hits on a web search - are you able to point me in the right direction of a product?