zlacker

>>belzeb+(OP)
> If it's so easy, why hasn't anyone done it before?

Medical 3D ultrasounds are a thing:

https://en.wikipedia.org/wiki/3D_ultrasound

That doesn't take away anything from how cool this project is though!

>>vander+oT
I guess that the main option is the second one. Lidars, once they are solid-state and cheaper will be a better alternative (smaller, more precise and much faster).

The first option isn't the good one. Ultrasounds are already used in car parking assists and people trying to improve them would have gone the same route as I did.