Orbit: drag to orbit, scroll or pinch to zoom. Overview returns to the full site.
Drone: drag to look, WASD to fly, Q / E to lower or raise altitude. Hold Shift to move faster.
Walk: drag to look and use WASD to walk. R returns to the entry.
On a phone, use the left pad to move and drag the scene to look. Drone altitude uses the up/down buttons.