
Show HN: We put an iPhone on the front wheel of a car - stelabouras
http://blog.evilwindowdog.com/post/88969373226/extreme-car-experiment-horizon
======
binarymax
I have some serious sea legs and almost never get motion sickness. The
fullscreen youtube vid got me. Great experiment.

~~~
NAFV_P
The video did make me feel quite queasy, but it is not as bad as _Descent_
[0].

[0]
[http://en.wikipedia.org/wiki/Descent_(video_game)](http://en.wikipedia.org/wiki/Descent_\(video_game\))

~~~
NaOH
I've never been a gamer. Except for Descent. And Descent II. I still have them
and every few years play them on an old Mac. The queasiness kicks in every
time I start playing them again.

~~~
adamkittelson
Oddly enough I had no problems with Descent / Descent II, but Doom and Doom II
wrecked me. I think it may have been because Doom's camera bobbed as you moved
to simulate taking steps but Descent's camera was smooth when you moved
forward.

------
Goosey
I found this to be really incredible. That is some amazing video stabilization
technology. If this app was available for android I think I would use it for
every video capture I ever do.

~~~
petrakeas
This is one of the developers of the app. The Android version will be
available in the following month. We are planning on running the experiment on
Android devices too!

~~~
HorizonXP
I've done quite a bit of work doing stabilization on Android. I think you'll
find the Camera APIs quite lacking. Are you doing image based stabilization or
using sensors? The fact you mention the gravity sensor tells me you're using
sensors.

Let me know, I'll be glad to help how I can.

------
FollowSteph3
Do NOT load from an iphone. Almost impossible to regain control of your
browser!!

~~~
Goopplesoft
Click url bar... Theyre using the new fullscreen api on iOS which kinda sucks
IMO.

------
stelabouras
Thank you for the support! Here are 5 promo codes so you can try our app for
free! [http://codehookup.com/2291e14c](http://codehookup.com/2291e14c)

~~~
BuildTheRobots
Absolutely blown away with the demo video (centripetal issues aside) though
annoyingly I'm one of those 'other' users, so I have to ask: Anything android
related in the pipeline?

~~~
moinnadeem
"This is one of the developers of the app. The Android version will be
available in the following month. We are planning on running the experiment on
Android devices too!" \- OP.

~~~
BuildTheRobots
Absolutely immense -will keep my eyes peeled =D

------
asciimo
This looks like something that iOS will incorporate as a native feature. When
they do this, do they usually buy the technology? Or the entire company?

~~~
vernie
Or just clone it and put the company out of business.

~~~
placeybordeaux
Is that really how apple has been working as of late? It's not like they
innovate on the software front all the time.

------
p00b
Very cool experiment, and even cooler visual results!

One thing though - the tilting of the scene from the phone's perceived
variance of the gravity vector is not due to centrifugal force, but due to
inertia.

In other words, it's the same reason you're pushed back into your seat when
you accelerate, and slam your head into the dashboard and spill hot coffee in
your lap when you lock up the breaks.

~~~
petrakeas
We also did an experiment with this:
[http://imgur.com/tdnympM](http://imgur.com/tdnympM)

The same problem existed. So it is not inertia in this case. However, inertia
could also interfere with the gravity vector.

------
rodw
What would happen if you put the camera closer to the outer part of the wheel,
rather than nearly centered on the hub?

Could Horizon still create a stable-ish video out of that (where the position
and rotation of the image are both changing rapidly), or does this require a
relatively stable position to work this well?

(I have no particular dog in this hunt, I'm just curious.)

EDIT: I see that Kayou asked the same question, probably in a smarter way,
here:
[https://news.ycombinator.com/item?id=7904992](https://news.ycombinator.com/item?id=7904992)
but I don't see a response from petrakeas or stelabouras yet, so I'll keep my
question here even if it is a little redundant.

~~~
stelabouras
Horizon corrects the wrong orientation regardless of the translation/position
of the device. Small translation differences along the X or Y axis can be
corrected by the stabilisation algorithm. Large translation deltas, however,
cannot be corrected.

So, if you put the iPhone on the outer part of the wheel you will most
probably get a horizontal video that will end up showing your scene moving up-
down, left-right.

------
smallegan
Bought the app, seems very laggy on my iPhone 5s. Is this to be expected? I
wonder if it is doing the processing as the phone is recording or if it is
capturing the accelerometer data and modifying the video after that fact?

~~~
uberspot
It's doing all the processing on the fly while it's recording.

------
ar_turnbull
A roller coaster might be a good experiment if you're looking for an extreme
environment that might appeal to more of a mass market.
([http://en.wikipedia.org/wiki/List_of_roller_coaster_rankings](http://en.wikipedia.org/wiki/List_of_roller_coaster_rankings))
Maybe skydiving or bungee jumping?

Or you could go a different direction and attach a phone to a cat. I hear
people love videos with cats ;)

~~~
frozenport
Phones falling off a roller-coaster could be dangerous!

------
zingermc
I poked around the website and their projects look awesome, exactly the kind
of stuff I'd make if I were more talented. I wish I lived in Greece because I
would find these guys and beg them to hire me.

------
lewisflude
A really cool way of showing off Horizon. Good work guys!

------
click170
They kept mentioning 'Horizon', took me a couple minutes to realize they
weren't talking about the BBC Series heh.

------
dested
Now this is viral marketing. Great job guys

------
TheCraiggers
Does anybody know of any software which can do this for videos which were
already captured?

~~~
mikeytown2
[http://www.guthspot.se/video/deshaker.htm](http://www.guthspot.se/video/deshaker.htm)
[http://avisynth.org.ru/depan/depan.html](http://avisynth.org.ru/depan/depan.html)

------
return0
Great job guys. Hope to see this integrated in the iPhone.

------
cratermoon
That's nausea-inducing.

------
martin_
It'd be really cool to see a side by side comparison with, and without Horizon
active

~~~
sb23
You can if you go to their website -
[http://www.evilwindowdog.com/horizon/](http://www.evilwindowdog.com/horizon/)

------
spada
will there be an API for this?

------
btbuildem
Kudos to you guys for trying to solve the VVS problem! For your second
experiment, may I recommend attaching the iphone to the disc of a variable-
speed angle grinder? You'll get a much larger range of speeds, as well as the
ability to aim the camera freely. You'll be able to test how your
accelerometer algos handle pitch and yaw IN ADDITION to centrifugal force!

~~~
petrakeas
Developer of the app here. One step ahead of you ;)

[http://imgur.com/tdnympM](http://imgur.com/tdnympM)

~~~
jacquesm
I hope you're joking. If you do plan on doing this then _please_ do it in a
suitably strong wire cage, power it on remotely, make sure it is tied down
very solidly and make sure nothing you care about (including you, significant
others, co-workers, children, pets, possessions etc) is in the plane of
rotation because this will fail spectacularly. Keep in mind that if the
grinder becomes dislodged or unbalanced that the plane of rotation may vary
rapidly. Too rapid to get out of the way. The iphone will desintegrate due to
the forces involved and the shrapnel will cause serious injury.

Please do not do this unless you really know what you're messing with (and if
you do then you won't).

On second thought, simply please do not do this. Spinning an iPhone up to 10K
rpm or higher is a very bad idea, the label reads 11K rpm max, 850W, those
things don't usually have soft-start so it'll just fire up and start throwing
things.

Appeal to authority fallacy comes free of charge: I've had a pretty serious
metal workshop and have seen several interesting interactions between angle-
grinders and various objects in otherwise controlled circumstances, it is
astounding how fast things can go wrong. Just having a grinder disc shatter on
you can take you completely by surprise even if you know the danger, this is
_far_ more dangerous, it is Darwin award material.

~~~
larrys
Really great points. I think that when working around power tools it is
sometimes forgotten how careful you have to be.

Everyone innately knows certain things like "don't stick fingers in light
socket" but other things aren't immediately obvious. Perhaps because you are
juxtaposing something like an iphone and maybe are focused on the worse case
scenario as being a destroyed iphone (in other words the money issue) instead
of the iphone flying off into someones face.

I was watching an episode of "Property Brothers" (a typical renovate a house
HGTV type show) and was amazed that they were having the owners participate in
demolition without using practically any protective gear (while using crowbars
and sledgehammers etc.)

~~~
sliverstorm
Crowbars & sledgehammers aren't power tools. It seems much more reasonable to
use those without significant PPE.

~~~
jacquesm
Hah.

Wait until you get a nice long steel nail that jumps away on you from the
crowbar just as it exits the wood and embeds itself 2" deep in _another_ piece
of wood. if you're lucky.

Or when a sledge hits a really hard pebble just off the side of a solid wall
and it gets catapulted out.

Sledges, crowbars and pickaxes are _really_ dangerous tools and especially if
you should wear goggles at a minimum, and probably a helmet too.

And, no, I'm not from the cradle to the grave coddling department.

~~~
sliverstorm
I absolutely buy they are dangerous, but are they as dangerous as a chainsaw
or big angle grinder? I'd take a nail 2" deep in my leg over a chainsaw in my
leg any day of the week.

(Personally I'd wear PPE with either type of equipment)

~~~
jacquesm
How about that nail in your eye?

Really, I can't stress this enough, the kind of energy you can imbue a 4" nail
with using a crowbar is something fierce.

Or maybe the crowbar would just fly up and split your head open. 4' of nice
steel makes one hell of a spring.

Big angle grinders are actually safer than small ones... until the disks
shatter, then you have a real surprise. Circular saws will do fun stuff as
well every now and then, they just love it when they get pinched in the cut.
So you have to plan how the material will warp before you start cutting
otherwise it might cause the dangling part to squeeze shut the cut (when you
want the opposite).

Chainsaw in your leg? Not good. Wear ballistic protective covering and you
should be fine. The clutch in your saw won't like it one bit but should you
ever need it you'll be very happy you spent that money, and a clutch is so
much easier to replace than a leg.

With a grinder you want to wear safety classes, _no_ gloves (so you can't get
caught). For chainsaws there are as many opinions on safety as there are
chainsaw wielders. Even the pros are surprised every now and then, usually not
by the saw but by the tree.

The best advice I can give you for saws is don't use one with too little power
and keep it sharp at all times (and that goes for all edged tools). Wear a
helmet with a screen and ballistic gear (pants, jacket).

If you're super experienced then you can make up your own mind and you'll
likely disagree with all of this :)

~~~
girvo
My dad is a builder, and I've worked for him as a labourer many many times. It
really gives you a better perspective on how dangerous all this is...

Anyway, circular saws: dad was cutting some pretty nice wood for a fence.
Circular saw hit something in the wood, bounced up, then straight down onto
his left hand thumb, severing it entirely.

He then drove to hospital. They reattached it, he was lucky enough to have
Australia's best nerve surgeon on call at that hospital that day, and now he's
got near 100% movement in it. Very very lucky.

Angler grinders blowing, now that's something that will put the fear of god
into you...

~~~
jacquesm
I agree your dad is very lucky. That's about as good an ending to that story
as you could possibly have. One day I was cutting staircase support (all those
triangles you have to cut out) from a 2" x 12" board, the same thing happened
and the saw just jumped right out of the cut. I slammed it down before it
could get out of control and it still managed to cut a really nasty gash into
the wood before it finally stopped moving. Incredible how fast that went from
everything fine to literally fighting the saw. Nobody got hurt that time so
all is well but still it gave me even more respect for rapidly rotating disks
of steel.

I had an angle grinder disc blow on me last fall when cutting through a
rooftile, that too was quite an interesting experience. It would have been
less of a problem if it had shattered completely but of course one segment on
one side decided to hang on. If not for eye protection that would have ended
in the hospital for sure.

The one thing I've noticed is that if you _rarely_ work with tools you are
really at risk. Then as you work more more with powertools you get more
experience, you become a bit more confident and more aware of the risks.
That's good.

Then when you're working with them for a really long time two things will
converge in a bad way: all that experience and confidence will lull you into a
false sense of safety an then the law of large numbers catches up with you,
very rare occurrences will happen to you because you are doing it so often.

If you're not paying attention right at that moment you could very well end up
in hospital or worse.

~~~
larrys
"all that experience and confidence will lull you into a false sense of
safety"

I've noticed that that happens with many different things in a similar way.

You get confident, you slip up, you work faster, you make mistakes.

When you start out boating (with a new boat) you are oh so very careful.

Then you gain confidence and you start to take more chances. All the sudden
things that you could never imagine yourself doing when you start you do. An
example might be getting caught in an inlet with a boat during a period when
larger boats are all trying to go in or out at the same time and you are
tossed left and right.

Programming as well. Say doing a rm -fr foo * in stead of rm -fr foo* and not
catching it because you hit return to fast instead of making sure the
statement was correct. [1]

[1] I got into the habit of doing for i in foo* ; echo $i ; done and then
inserting the rm -fr statement (by using uparrow) just as a precaution to slow
me down.

~~~
jacquesm
> I got into the habit of doing for i in foo* ; echo $i ; done and then
> inserting the rm -fr statement (by using uparrow) just as a precaution to
> slow me down.

I do the exact same thing only I use 'ls foo*' first, and when doing bulk
updates / deletes with sql servers I again first do a select and then modify
the select once I'm sure it will hit the right rows.

------
thisjepisje
Drive faster god darnit!

------
ekosnow
oooohh!!! great experiment with great results!!

------
sek
Why not a GoPro on a wheel?

Edit: I just think I should've googled that first.

~~~
protomyth
I would guess a GoPro doesn't allow Apps nor has the sensors accessible to
perform the experiment with an external computer.

[edit] I do wonder why we haven't seen more programmable cameras with the
sensors a smartphone has.

------
S4M
...And it's interesting because?

~~~
ctdonath
Because the focus of the experiment is an app that records videos while
compensating for tilt/rotation (it's not just "hold muh beer while I tape my
iPhone to a car wheel!"). I have the app, and find it interesting for its
ability to eliminate the inevitable angling of the video, despite being on
such an unstable mount (my free-waving hand). By subjecting the app to extreme
conditions of rapid rotation, subtle flaws in the compensation process are
made apparent - specifically, that the iPhone's gravity sensor gets confused &
skewed, that the progressive scanning of each frame means distorting the image
(the top of the image shows a view 1/60th or so of a second different from the
bottom), and the two together result in a bizarre/unexpected periodic warping
of the image. Having this video, the experimenters can go back to the software
lab and tweak their image processing algorithms to compensate for these errors
and create an even more stable image.

"So what?" you mumble. "It's so subtle nobody cares."

Well, that's actually a big part of why VR failed when it was first introduced
a couple decades ago, and why Carmack & Occulus are so successful with it now:
they've analyzed the subtle nuances that you don't acknowledge but your brain
processes & reacts to nonetheless. Horizon is applying the same attention to
detail, and will produce a better product as a result (yes, I do notice those
sub-frame distortions in various products almost daily, and would appreciate
developers correcting them).

------
universome
Cool experiment, I just dont get, how that idea came to your mind? \- "Oh,
man, look, I have an iPhone. Guess what?" \- "Yeah, we should certainly put it
on a wheel of a car!"

~~~
cgh
Starting from the second sentence in the article:

"We all know by now that Horizon shoots perfect horizontal videos, even if you
rotate your device while shooting! We wanted to stress Horizon’s capabilities
by using it under extreme circumstances."

------
bra1n
Better title: "Show HN: We put an iPhone on the front wheel of a car and drove
really slowly for less than 10 seconds at a time"

~~~
Raphmedia
50 km/h is fast enough for this experiment if you ask me.

