
3D scanning like a pro - SauliusLukse
http://kurokesu.com/main/2017/05/08/3d-scanning-like-a-pro/
======
femto
CSIRO/Data61 have demonstrated with their Zebedee system [1], that the
precision mechanical system is optional. Their handheld LIDAR head bounces
around randomly and the system is able fit and register the new measurements
within the 3D model that it is progressively building.

Such a handheld LIDAR would be a very cool hobby/amateur project, as the
mechanical side can be simple and low cost, making the capital cost low. The
smarts are in the software and maths. There is also that fascination/aha
factor of working though the maths and realising that smart processing means
that some "obvious" things, such as precision mechanics, aren't actually
necessary, then seeing it work.

[1] [https://www.data61.csiro.au/en/Our-expertise/Expertise-
Cyber...](https://www.data61.csiro.au/en/Our-expertise/Expertise-Cyber-
physical-systems/Zebedee)

~~~
danseagrave
And it not just a demonstration.

At GeoSLAM (joint venture with CSIRO) we sell scanners and software based on
the Zebedee (ZEB1) and a mechanically rotating version (the ZEB-REVO [1]).

The rotating version is easier to use (don't have to worry about nodding the
head too fast or too little) while still having the same cost/speed advantages
over terrestrial scanners.

[1] [http://www.geoslam.com/hardware-products/zeb-
revo/](http://www.geoslam.com/hardware-products/zeb-revo/)

(disclaimer, GeoSLAM employee)

------
mikeha
Great project! but the title "3D scanning like a pro" is quite a stretch. Real
3D scanning pros use something like this Leica P40 scanner:
[https://www.youtube.com/watch?v=GnmerVV5-T4](https://www.youtube.com/watch?v=GnmerVV5-T4)

And produce outputs that look more like these: [https://truviewglobal.leica-
geosystems.com/welcome](https://truviewglobal.leica-geosystems.com/welcome)

(full disclosure: I work for Leica Geosystems).

~~~
mentat
"like" meaning not "as". I was unaware anything could be done for low hundreds
of dollars. That's very interesting. Looks like your system is > $100k?

~~~
joshvm
The definition of pro varies! Here's a short rundown of 3D imaging:

Laser triangulation systems (laser stripe + turntable) will give you extremely
highly detailed models at close range. You could build one for under £100 and
the accuracy can easily be sub-mm. Downside is it'll only work for a short
range.

Long range you're not going to beat a scanning LIDAR system like the sort that
Leica offers. A comparable system from Faro (with a public price-tag) is
around £30-50k depending on spec. For 'set and forget' scanning, these systems
are great. They're also pretty much the only reliable solution for robust,
kinda fast capture of large sites. Velodyne's automotive LIDAR (the one on the
older Google cars) came on the market for around $75k. The future of 3D
imaging is _probably_ low cost MEMS scanning LIDAR, which is being bankrolled
by autonomous driving.

Short range you also have time of flight (Kinect 2) which is used in research
and also by several large companies for commercial RnD (e.g. Ocado -
[http://robohub.org/wp-content/uploads/2017/02/SoMa-Ocado-
RBO...](http://robohub.org/wp-content/uploads/2017/02/SoMa-Ocado-RBO-
Hand2.jpg) \- see the thing on the tripod?). My local second hand stores sells
the Kinect 2 for about £25, but you need the USB adaptor (£30). Lots of
companies make ToF sensors, but Microsoft really forced the price down.

Then you've got Kinect 1-like systems (Primesense), which include Google Tango
(and other clones from Asus, etc). I think the Intel Realsense does something
similar. These are mono cameras and an IR pattern projector. They don't work
in sunlight, but are pretty good indoors. The Kinect 1 was (is) huge in 3D
vision research because it was so cheap and relatively robust.

Finally you've got stereo which is the only real competitor to LIDAR outdoors.
Much more dense than LIDAR, and you get true intensity information, but poor
accuracy at long range. Performance is mostly dependent on the distance
between the cameras. It's also the only technology you can reliably use in
space. There are very few spaceborne LIDAR systems (e.g. LOLA, MOLA, etc).
Stereo is the bread and butter of 3D on rovers and for planetary mapping.
Prices vary, but you're looking at around £400-500 for a _good_ pre-built
stereo rig.

I think it would be unfair to say NASA and ESA (Exomars should also have
stereo cams) aren't pros!

There are also several niche industries like handheld structured light
scanners which can also get sub-mm accuracy. These are used for a mix of
industrial inspection, capturing props for movies, etc.

~~~
fest
You can also take the Kinect 2 apart and modify it for using external power
input and regular USB3 (Type B?) cable. I have done that and it works well,
see: [http://www.tatsch-it.de/kinect-2-usb-3-modification/](http://www.tatsch-
it.de/kinect-2-usb-3-modification/)

------
ReligiousFlames
By comparison, actual pro scanning: matterport grabs textures and verticies
simultaneously, originally using a Kinect.
[https://matterport.com](https://matterport.com)

Here's an DIY instuctable (untested) which also uses a Kinect
[http://www.instructables.com/id/EASY-
Kinect-3D-Scanner/](http://www.instructables.com/id/EASY-Kinect-3D-Scanner/)

The Kinect range IIRC is less than most LIDARs so it won't be 1:1.

~~~
rsp1984
And since we're in shameless plug territory already:

By comparison DotProduct [1] is doing full 3D model creation on tablets since
2013 (our first product was based on a Google Nexus 7 with just 1 GB of RAM --
no cloud required).

[1] [https://www.dotproduct3d.com/](https://www.dotproduct3d.com/)

~~~
seanccox
Maritime Archaeologist here: we take photos with a DSLR camera of terrestrial
and underwater sites, and artifacts, and then extrapolate 3D models with
Agisoft Photoscan.

Is there any advantage to using one of these devices?

~~~
rsp1984
> Is there any advantage to using one of these devices?

Yes, you can get the fully processed 3D model within minutes of capture, no
cloud or desktop computer required. Plus our file format is very compressed so
you can share scans right from the field over your mobile connection.

------
netinstructions
Another way of doing this is something like Google's project tango, right?
[0][1]

So you can build and code this up (which sounds like a fun project) or if
you're lazy or lack the time you can buy a $512 portable device that probably
has an app or two to do 3D scanning out of the box.

Both approaches have their pros/cons but both are pretty neat and it's
exciting that it should only be cheaper and easier for hobbyists to play with
in the years to come.

[0] [https://youtu.be/Qe10ExwzCqk?t=34](https://youtu.be/Qe10ExwzCqk?t=34) [1]
[https://www.youtube.com/watch?v=9_GD7kUbogk](https://www.youtube.com/watch?v=9_GD7kUbogk)

------
nuntius
Some of the visual SLAM techniques are also getting fairly good results for
cheap. In particular, see DSO (same research group as the previous LSD-SLAM).

[http://vision.in.tum.de/research/vslam/dso](http://vision.in.tum.de/research/vslam/dso)

~~~
eerikkivistik
Nice paper, hadn't seen this one before, seems pretty recent.

------
EvanAnderson
Is there any economical (we'll say sub-$2K) method that an individual can
produce 3D scans of typical interior residential spaces? I've taken a lot of
2D photos of various places that are sentimental to me, but I'd love to make
even low-quality 3D scans if an economical option existed.

The Matterport product mentioned elsewhere in the comments seems interesting,
but they specifically disclaim that they don't offer a local hosting option.
Since this is for personal use I really just want the data from the scans, not
a recurring service model.

Edit: I'll clarify. Is there a "packaged" scanning hardware product in the
sub-$2K range? I don't follow this technology closely and I'm really just
sticking my head in to see where things are right now? I'm all for cobbling
together software to deal with the resulting output, but I'm not in a position
where I can cobble together hardware.

I don't know enough of the associated terminology, so I sound wholly
uninformed here. What I see in the linked article are point clouds, which are
definitely interesting, but I'm wondering if something exists to allow an
individual to capture textured scans and store/view them on their own
hardware. The Matterport product looks like what I'd want (at a $3.6K price-
point for the camera, and arguably with higher quality output than I desire)
but it sounds like it's really a service offering and doesn't just give you
the resulting data for your own use w/o their recurring service.

~~~
leoedin
Is this article not literally about doing 3D scans of interior spaces using
cheap components? The stuff listed in the article costs $549 (plus a
laptop/arduino/tripod etc).

~~~
EvanAnderson
I dropped on an edit. I'm a rank amateur here, and admittedly trying to use HN
readers' knowledge as a substitute for research I should be doing on my own.

------
arjo129
Completely unrelated shameless plug: Reminds me of my toy 1 led 3d scanner. I
haven't had more time to play with it.

[https://arjo129.wordpress.com/2017/01/08/diy-3d-scanner-
via-...](https://arjo129.wordpress.com/2017/01/08/diy-3d-scanner-via-inverse-
square-law/)

------
joshvm
This is cool!

I built essentially the same kind of contraption for my PhD, except I used a
gimbal scanner (±90 degrees in two axes) and an industrial 1D LIDAR (a Dimetix
FLS-C). You get some interesting calibration problems, because if your LIDAR
isn't perfectly centred on the rotation centre of both axes, you'll get
offsets; in one direction you'll overshoot, in the other you'll undershoot.
The basic trig works well enough for demonstrations though.

Similar downside: the LIDAR I used was extremely accurate (±1 mm stdev), but
could only capture at around 20Hz. 500Hz would have been a luxury! I believe I
could have pushed it to 200Hz with analogue out, but I wanted the accuracy.

------
gavanwoolery
had an idea to scan semi convex objects using a web cam and a green screen
(something like this has probably been done before Im guessing). Just trace
the outline of the object at various rotations (i.e. using a turn-table) and
produce a model from the result. Probably do two passes, rotating the object
90 degrees on its side for the second pass.

~~~
joshvm
Yup, this is called shape from silhouette. Quite a lot of research on it over
the years:

[https://www.cvg.ethz.ch/teaching/compvis/2011/lecture/vision...](https://www.cvg.ethz.ch/teaching/compvis/2011/lecture/vision08.pdf)

EDIT: Better link

~~~
eon1
See also: Visual Structure from Motion, which I believe works off static light
sources (same stuff you see in 123D Catch and similar software, this one is
free though).

[http://ccwu.me/vsfm/](http://ccwu.me/vsfm/)

For a less detailed/easier to use process, you can also try Regard3D:
[http://www.regard3d.org/](http://www.regard3d.org/)

~~~
jsch
Another open-source, full 3D reconstruction pipeline is COLMAP:
[https://colmap.github.io/](https://colmap.github.io/)

------
tekromancr
Bravo! This is really impressive! I have always wanted to do something like
this with a kinect, but I think I like this method way more because of the
lack of any black boxes. You can really see how the whole thing works, top to
bottom.

------
batmansmk
Beyond the technical tour de force, I find the visual results artistically
pleasing. Androids definitely dream of electrical sheeps.

