N flies to the next spot (gold number), 1–9, 0 to any spot. Walk with W A S D or the arrow keys (← → turn); mouse or drag to look. Near a spot its clip plays. Esc frees the mouse for the panel on the right; click the room to walk again.
Aim the circle at a surface while walking, press Esc, type, then "Mark this spot". The marked spot is saved in this browser. To build the real 3D item, run
pipeline/add_item.sh with the downloaded file; the item then appears for everyone.