On a Meta Quest 3, open 0xr.space, open any model, press View in your space, then press Scan on the dock. Boxes appear round the things Scan recognises, held in place in the room, each with its name; the one you look at also shows its size, such as 44 x 15 x 3 cm. Press a name, or say it to Zero, and a panel opens with a photo of the thing, its size, how far away it is and what the scan called it, while Photo → 3D makes a model of it.
Scan is experimental and names 42 kinds of everyday things. Anything else gets no box unless you say its name, which Scan then looks for in a few seconds. Things over a metre are drawn as an outline. It works in good light, on Quest 3 only; a Quest 3S takes one photo instead of showing boxes.
Things on a table or in a hand, such as cups, bottles, bowls, cutlery, phones, keyboards, laptops, books, clocks, vases, plants, fruit, bags and teddy bears, and bigger things: chairs, couches, beds, tables, fridges, ovens, sinks, suitcases, bicycles and TVs.
Scan learned from everyday photos and can be fooled, for example by a camping fridge it calls a suitcase. With Zero on, Zero looks at the photo and puts its own name and a sentence or two on the panel.
They are closest for things within reach. Treat them as a guide, not a ruler.
See the privacy page at https://0xr.space/privacy/ for what the camera features send and keep.
No. A scan in a dark room stops by itself and makes nothing.