That would be very nice

.
As it is, however, we know that cameras can see 15m. So it's not that hard to make a physical template built around a camera with a bunch of 15m spokes sticking out either spherically or hemispherically. Then just move that around to let you know where to place the next camera. I used to have such a template on my workshop but it's such a trivial thing to make, and the need for it is so annoying, that I took it down.