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The lidar on the phones suck (I had one and was super disappointed). It has a range of like half a room, terrible resolution, was slow as heck, and the software
by technobabbler 5y ago
The lidar on the phones suck (I had one and was super disappointed). It has a range of like half a room, terrible resolution, was slow as heck, and the software was buggy and unstable and the algorithms often butchered all but the simplest scans. It's not like you put the phone on the tripod and you get a Ubisoft-like cave in a minute. It's like you get half the room at 20% fidelity after an hour of frustration.
Honestly the more mature photogrammetry techniques that stitch together multiple photos (from video or 360 shots taken successively) seemed much more impressive. Indeed, you can run most of the same apps with lidar off and still get similar results. There is a lot of depth info when you take pictures from different angles that a smart algorithm can figure out. The lidar adds more hinting but without professional grade equipment, the optical sensors (cameras) are much higher resolution and range.
The lidars on the i devices are cheap gimmicks.
Edit: just to add a bit more detail, lidar basically gets you a point cloud of depth data. The professional ones have big spinning mirrors that blanket the room in a matrix of powerful dots, like a Kinect on steroids. That takes a lot of power and, usually, moving parts.
The iPhone one uses more modern, smaller solid state technology but has a resolution of a few hundred dots and a range of 5m, vs the millions of pixels on the optical camera and a range of however much ambient light you have.
The lidar is an active emitter. It has to produce its own laser light, limited by its emitters and battery, and have a way to scan its emissions across 2d space (x and y axes) or else have a ton of micro lasers in a grid.
By comparison the optical camera is just a passive receiver, accepting reflected sunlight or light from the the weak LED flash. Those light sources are way stronger and more diffuse in terms of range and coverage.
Maybe in a few years the lidar will get better but for now it's just not useful for anything except face ID. Prosumer drones probably have better lidar and also better photogrammetry software.
More deets on i lidar: https://arstechnica.com/cars/2020/10/the-technology-behind-the-iphone-lidar-may-be-coming-soon-to-cars/ https://arstechnica.com/cars/2020/10/the-technology-behind-t...
- andybak 5y agoThere's some fantastic results here: https://sketchfab.com/search?q=iphone+lidar&type=models https://sketchfab.com/search?q=iphone+lidar&type=models And these match what I get - they aren't anomolous. It's not as good as photogrammetry but it takes minutes rather than hours.
- Tams80 5y agoNot terrible, but not good enough for most uses.
- andybak 5y agoWhat "uses" are you thinking of? It's not going to replace industrial laser scanners for surveying and site inspection but it's good enough for many of things we're currently using photogrammetry for. And the sheer ease of use could open up new applications that wouldn't have been viable with slower workflows. Speed is a feature in it's own right.
- technobabbler 5y agoYou really think those are fantastic? The only ones that seem even remotely good are the knew where the camera rotates around a static object (couch, whatever). For the room scale ones, the results are terrible. Like this one of the sketch fab hq: https://sketchfab.com/3d-models/sketchfab-hq-scanned-with-iphone-12-lidar-bbd645372b654d829d83626af68af634 https://sketchfab.com/3d-models/sketchfab-hq-scanned-with-ip... It looks like something out of a video game dream sequence where your world is falling apart.
- andybak 5y agoThey are roughly comparable with results from photogrammetry at a fraction of the capture/processing time. Have you seen much raw photogrammetry output? Before it's been repaired/cleaned-up? You can get better than this with photogrammetry but it takes a lot of time and trial and error. This stuff is as good as my personal attempts at photogrammetry and in some cases better. When photogrammetry fails it generally fails catastrophically. With LIDAR you will always get something.
- technobabbler 5y agoI think we generally agree. I'm just saying it's not good enough to take into a cave and casually scan it into a 3d model yet, not with the cheap consumer tech at least. I don't think those results are usable for anything (games, sharing, measurements, mapping), just novelty.