the drones are doing 3D from stereo. My understanding those autonomous cars we see around SV don't do it (except for some Ford sedans - probably Ford venture - who have what looks like stereo for the front view). Google and some others build 3D from lidar - it is almost as good as stereo though much less resolution. The low lidar resolution is close to being good enough for the street driving while it wouldn't work for the forest at meaningful speeds (even if somebody managed to place a lidar on drone)