[HN Gopher] 3D Scanning Systems That Can Render a Complete, Edit...
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3D Scanning Systems That Can Render a Complete, Editable 3D Model
in Minutes
Author : simonebrunozzi
Score : 31 points
Date : 2021-03-21 07:55 UTC (1 days ago)
(HTM) web link (lynceans.org)
(TXT) w3m dump (lynceans.org)
| holoduke wrote:
| Every once in a while I start looking for a great affordable 3d
| scanner. Is there something like the equivalent of the prusa 3d
| printer for 3d scanning?
| errantspark wrote:
| No because 3D scanning is really, really hard. Much much more
| complex than 3d printing. There's no fool-proof way of
| determining the position and normal of a surface point other
| than to touch it. All EM based techniques must contend with the
| wide gamut of different interactions common materials will have
| with a given wavelength. Not to mention occlusion.
| CobrastanJorji wrote:
| Good question. There are several 3D scanners in that price
| range, but I'm curious as to the difference between
| photogrammetry with a phone, something like the $800 SOL 3D,
| and the $10k+ handheld options.
|
| The ~$1k 3D scanners out there advertise an accuracy of
| something like "up to 0.1mm," which puts them in the ballpark
| of the resolution a basic Prusa's likely to be able to
| reproduce, but I'm really unclear on how true that is in
| practice.
| errantspark wrote:
| There's likely some actual Nyquist-Shannon ish corollary that
| will tell you how much higher your scanning res has to be
| than your printing res, but 2x is probably a safe bet. Not to
| mention "accuracy" tells an imprecise story. Does it mean
| that the best case scenario every point is at most 0.1mm from
| where it should be? That doesn't mean the same thing as
| "accurately resolves features larger than 0.1mm3".
| valine wrote:
| Any iPhone with FaceID is actually a very capable as a 3D
| scanner. I recommend heges, it has support for Lidar scanning
| as well (if you have an iPhone 12 Pro or a new iPad Pro).
|
| https://hege.sh/
| nobbis wrote:
| Cubify was a rebranded Structure Sensor, which was a Primesense
| camera, which was the original Kinect (that Apple bought in
| 2013.)
|
| It used structured light: project a static pattern of infrared
| dots and then measure parallax using an infrared camera a couple
| inches from the projector to calculate depth. It worked well, but
| can't be miniaturized as it relies on a large offset between
| projector and camera. Orbbec make similar cameras today, e.g.
| https://orbbec3d.com/product-astra-pro
|
| Modern depth cameras, like the LiDAR Scanner in iPhones and
| iPads, use a different technique: time-of-flight (ToF), which
| shoots laser pulses and measures the time taken to reflect back
| to infer depth. Apple leads the field here, because they're the
| first to integrate a "direct" ToF sensor into mobile devices,
| which has a number of advantages over the "continuous wave" ToF
| found in Android phones.
| burntoutfire wrote:
| Do you know if purely vision based techniques have any
| advantages for inferring depth in these scenarios (close range
| object scanning) over lidars?
| nobbis wrote:
| Yes, different failure cases (purely vision can't tell the
| depth of a plain white wall) but there are orders of
| magnitude more pixels in regular cameras. Apple's LiDAR
| produces a 256x192 depth map, but its RGB cameras run at
| 1920x1440. You get much more detail, but passive stereo is
| orders of magnitude slower (ToF sensors are 60 Hz,
| photogrammetry takes minutes.)
|
| They complement each other well, which is the basis of our
| approach at Abound: combine the detail of multi-view stereo
| for short-range with the robustness of ToF out to 5m.
| slobiwan wrote:
| This is a pointer to a review from 2015 for a product that's no
| longer commercially available. Seems like perhaps the technology
| wasn't as mature or capable as the review seems to indicate, if
| it didn't make it.
| vertis wrote:
| Having owned and used the device I can attest to that. It was
| hard to get it to work reliably, and it certainly couldn't
| handle either small finely detailed items or bigger spaces like
| whole rooms.
|
| It would do part of a room fine and then lose tracking and
| never be able to re-establish tracking and you would have to
| start all over again.
| errantspark wrote:
| The V2 (Structure Core) has a built in IMU and is much better
| at keeping tracking. The quality of the USB link between the
| sensor and the computer also makes a big difference. (not an
| expert in this particular area) but iirc USB is like TCP in
| that if a packet is missing or corrupted it'll ask for it to
| be resent, it seems like the Structure sensors are quite
| sensitive to this and missing more then a few frames leads to
| alignment issues. That being said I wouldn't call the
| experience user friendly on any level, their software is
| really really bad too, I've had to write some tools to modify
| their save files so that I can rotate the reconstruction area
| because that's not a feature of the software. Definitely
| strongly dis-recommend buying one.
| ffffwe3rq352y3 wrote:
| This could be a big deal for games Games Workshop and Warhammer
| like games in general. I don't think this could copy model
| because they are so small and detailed but the technology is
| advancing quickly! Why bother buying the models when I can 3d
| print them OR port the 3d file into TTS and play online?
| errantspark wrote:
| Because buying the models even at GW prices is likely cheaper
| than the time and effort necessary to do a good job of printing
| them. Model piracy does occur but it takes the from of Chinese
| recasters making molds directly from the model sprues. That all
| being said there _is_ a market for this and my guess is the BOM
| cost of the hardware necessary to make a 3D scanner capable of
| resolving the detail of a tabletop mini is in the $10-$30 range
| right now. No way there 's enough market to foot the bill of SW
| dev tho.
| ffffwe3rq352y3 wrote:
| Yeah with the current tech it isn't really worth it to print
| stuff unless its like an entire army and you would be ok not
| using GW models. However, in the future I'm betting this will
| change and It will be much cheaper to print the models at
| home or have someone you know do it!
| simonebrunozzi wrote:
| I wish I had a system like this when I was a kid, and spent a
| the equivalent of a few hundred euros over the course of a few
| years to buy just a few of these miniatures. These prices were
| simply outrageous, especially outside the UK.
| ilaksh wrote:
| You can search for 3D scan in your app store for current
| products and then try it.
| belval wrote:
| This is based on structured/coded light and as such is basically
| useless for most surfaces that will not reflect light (think most
| black things) or very reflective things (think metal). I have an
| SR300 which was intended for face scans and it works very nicely
| for humans but I tried to scan other surfaces for a school
| project[1] and the limitations became obvious very fast.
|
| [1] https://github.com/Belval/Scanner3D
| valine wrote:
| These scans don't look any higher quality than what you can get
| with FaceId or lidar on the iPad Pro. It's a product from 2015 so
| I guess it could have made sense back then.
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