I was wondering, what wouldn't work for sensor placement. What is the maximum distance it would work at for instance, could I mount them on the ceiling at a 45 degree angle, etc?
If you only use front facing software : For the best hand tracking place both cameras in front of you (apparently even the two PSVR cameras work out despite being barely apart from each other, and same goes for the two eyes on your face).
If you want standing 360° : Place them in opposite sides (I suggest trying with one in a top corner, and the other at the opposite BOTTOM corner, of a perfect cube, which might provide better hand tracking for picking items off the ground then placing both cameras above you).
If you want room scale (the ability to walk around every corner of your room) : That's when you need a third camera, placed at ~120° from each other (and ~90° from each other with four cameras). If you don't get the third camera you'll risk serious hand tracking occlusion issues when moving towards one of the two corners (or sides) of the room that has no camera on it.
In my case my room is only ~7x7 feet (2x2 meters), with that kind of VR space moving even one step away from the center is an invitation to smash my hand controllers into something (tested, works fine), so I'm going with 2 cameras because if I'm moving towards a poorly tracked corner/side of my room, I'm doing it wrong and should be pulling right back to the center.
To try out the 2 camera in opposite corner setting for 360° standing VR try picking up items all around you from the ground (to determine the best height for each camera) then shooting a virtual bow/slingshot in every direction (which maximizes occlusion issues by requiring to place your hands at the same height but at opposite lengths from your body), and if that works out for you then odds are you don't really need to spend an extra ~80$ on a third camera for 360° standing VR.
