mattbell: (Default)
2011-01-02 11:14 am
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Multiple Reality Acroyoga - More Fun with Kinect

I've been working on other things with the Kinect, but I do want to keep making multiple reality videos.

I got a couple of friends who do acroyoga to come over.  Here's what we made:

In case you haven't been following along:

I wrote some software to merge multiple 3D video streams captured by the Kinect into a single 3D space. Objects from each video stream are superimposed as if they occupy the same physical space, with nearby objects from one video occluding more distant ones from another. Sometimes objects overlap, creating interesting mutant forms.
mattbell: (Default)
2010-12-13 12:24 pm
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Merging multiple 3D Realities with the Kinect camera

I wrote some software to merge multiple 3D video streams captured by the Kinect into a single 3D space. Objects from each video stream are superimposed as if they occupy the same physical space, with nearby objects from one video occluding more distant ones from another. Sometimes objects overlap, creating interesting mutant forms.

Next, I want to make 3D-merges of cats, dancers, silk aerialists, martial arts experts, that painting Nude Descending a Staircase, that scene from Alien, and much more...

Also, I want to take a moment to send some hate in the direction of WMG for blocking the original audio track on this video (KT Tunstall's Black Horse and the Cherry Tree, which was *perfect*), forcing me to re-edit the whole thing with a new song. They need to get with the internet age and realize that they shouldn't say no to awesome free advertising.
mattbell: (Default)
2010-12-03 09:56 pm

I create "ghost furniture" with the Kinect 3D camera

 Lest I be getting lazy on a Friday night, I made a 3rd Kinect video.   Here is another fun thing you can do with your own software on a 3D camera:

By taking a 3D snapshot of the room with furniture in it, I can remove the furniture and then wander in the 3d "ghost" space left behind.
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2010-12-03 09:31 pm

3D "Depth Strobe" -- Sculpting in 3D using copies of my own body


I made some improvements to my program from yesterday.  Now I can control how multiple RGB/Depth images are merged together to create a virtual 3D sculpture I can walk through.  This stuff is seriously fun.

mattbell: (Default)
2010-12-03 11:33 am

Surrealist 3D sculptures using a hacked Kinect - help me make more!


I believe that consumer-level 3D cameras will have a huge impact on a variety of industries and will lead to the creation of many types of new products.  I've started to play around with the Kinect using the OpenKinect hack & open source codebase.  

For my first project I created a 3D sculpture tool.  In the video, parts of the sculpted image become updated when an object in that area moves closer to the camera than any other object has been in the past.  This lets you carve images in space by moving them closer to the camera.  This took a day of intense work -- I'm planning on making some upgrades to it over the next few days to make it even more interesting.

I also would love to shoot some more videos.  In particular, I want to do the following, though I'm totally up for experimenting and playing with different things:
- People doing acrobatics
- Dancing (especially couples dancing, like waltz)
- Recreating the painting Nude Descending a Staircase (nude or not-nude).  I need a better staircase than the one in my house
- A playful cat chasing things (preferably light or multicolored cat with short hair.  I don't think the camera would do as well with cats with long black hair)
- Moving the camera through lots of houseplants, or just one that is blowing in the wind.

Also, if anyone has a recommendation for a better Mac screencapture program, I'd love to hear it.  The one I downloaded last night hiccups and causes other issues.
mattbell: (Default)
2010-10-20 06:06 pm
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Hang gliding

Hang gliding induces the most intense mental flow state I've encountered in a long time. The instructors at Mission Soaring have also found a method of instruction that provides a smooth challenge ramp that makes it easy and safe to start. It's a good combination. My best flight from my first day:

Also, I think taking videos is a really useful learning tool, and I'd recommend it for other sports. My gliding partner and I took turns videoing each other.

Furthermore, if you think I'm gambling with my life, please read this report by the USHGA (summary: 1-2 deaths a year in the US since the late 1990s) and take into account that the hang gliding community includes people who fly with no harness on rough currents close to the ground and people who do acrobatics that their glider was not meant to do.  This means that the risk for relatively risk-averse people is substantially lower.  The USHGA is good about having a strict rating system and not certifying pilots who cannot pass specific tests.
mattbell: (Default)
2010-09-22 12:50 pm
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Topping Jessica

At the local indoor rock climbing gym, all the routes are given names.  Usually the routes in a given area all have names along a similar theme -- eg whiskies, Shakespeare plays etc. 

One section of the gym has routes named after sweeteners. 

"Sucralose, aspartame, saccharin, xylitol, Jessica, fructose, glucose"

Jessica?  I'm sure there's a story.  Maybe it's one of the route setters' girlfriends.  In any case, despite her sweet demeanor, the run by her name is one hell of a challenge.  However, it's a very interesting run, with lots of lateral moves and unusual holds.  I found myself drawn to Jessica, but repeatedly rebuffed by her (5.11a) tricky route.  I tried to get to the top several times over the last month, usually falling 4-5 times along the way if I made it to the top at all.  I had much of the route memorized.  Obsession brewed.  I worried that the route would be taken down before I had a chance to make a clean ascent.

Yesterday, we all decided to film each other at the gym to study our technique, so I happened to get onto film my first successful clean attempt at topping, err.. mounting... uh... summiting, conquering, climbing... oh I give up... Jessica. 

If anyone wants to give climbing a try (if you can climb a ladder, you can do a beginner route!), let me know.  This Friday is bring-a-guest-free day.
mattbell: (Default)
2010-06-02 10:07 am
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Sleep talk now online

My talk on Sleep Hacking from the May Quantified Self is now online. Thanks, Alexandra!

Matt Bell - Hacking the Sleep/Wake Cycle from Loren Risker on Vimeo.

mattbell: (Default)
2009-12-15 11:17 am

Sleep video

Some material from my Quantified Self presentation on sleep self-experimentation is on Wired's blog today.


Some Q&A:

> Why are you doing these sleep experiments?

I'm hoping to improve my amount of wakeful, pleasurable, and productive time during the day by improving my sleep. I've been specifically trying to shorten sleep latency and decrease awakenings during the night.

> You've done some experiments with drugs. What works best? What sucks?

I tested sleeping pills for two things -- effectiveness at getting me to fall and stay asleep, and the amount of "hangover" I experienced during the next day. I found two types of sleeping pills that worked best for me. Melatonin was best for typical situations, as it was moderately effective and had almost no hangover effect. Ambien was best for extreme situations (eg a noisy bus) as it was highly effective and had only moderate hangover effect. Ambien also had the nice side effect of resetting my circadian rhythms, so it's great for adjusting to new time zones when traveling internationally. Diphenhydramine HCl (the active ingredient in most over-the-counter sleeping pills) was the worst as it was moderately effective but produced a very strong hangover effect. I noticed that it also tends to lower my sleep quality by dramatically increasing the amount of snoring and number of apnea events.

Of course, effectiveness and side effects vary from person to person. I am not a doctor. Consult your doctor before [disclaimer] etc.

> What advice do you offer to friends who want to improve their sleep?

Different people have very different sleep issues. Some people have difficulty going to sleep. Others have difficulty staying asleep. Still others have a lot of awakenings during the night.

As a result, I'd recommend tracking the aspects of sleep you have trouble with and experimenting with various factors to see how they affect your sleep quality.

Some factors I'd recommend experimenting with include:
- If you share a bed, try a queen (or better yet, a king) bed and get one quilt per person so that your partner's sleep movements are less likely to disturb you.
- Get some aerobic exercise every day.
- Don't do stressful things (work, arguments etc) late at night.
- Lower the lights during the last couple of hours that you're awake.
- Play with your diet. Don't eat large amounts of protein (or large amounts of food in general) late at night.
- Try a range of sleeping pills to find one that works well for you on nights where you can't fall asleep naturally.
- Use curtains and timed lights to control the morning onset of light in the bedroom.
- Sleep with earplugs.
- Change sleep posture (side vs back vs face down)

It is of course worth talking to sleep specialists as well. The Stanford Sleep Clinic is one of the best in the country.

> After your experiments, what were you surprised about?

The biggest thing that surprised me was seeing how much I moved around while sleeping. It was fascinating to glimpse the workings of this hidden unconscious world that occupies close to a third of our lives.

mattbell: (Default)
2009-11-23 11:12 pm
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[travel] Leafcutter ants carrying leaf-surfing ants

In the Arenal rainforest in Costa Rica I captured a rather unusual sight. Leafcutter ants are amazingly cool -- it was impressive to watch as a long line of them marched back to their colony, each carrying along a large piece of leaf or flower. As I zoomed in on one, I noticed that the leaf it was carrying had another ant (of some smaller species, it appeared) confusedly walking around on the bit of leaf carried by the leafcutter ant.

The leaves are not used directly as food but instead are used to "farm" a fungus eaten by the ants.
mattbell: (Default)
2009-10-22 12:31 am
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Freaky horned melon

I got this at Berkeley Bowl a couple of days ago:

This tropical fruit is like something out of Aliens. It's full of jelly-covered plant embryos suspended in a matrix of some connective tissue. When I squeeze the melon, the embryos pop out of the matrix.
mattbell: (Default)
2009-10-13 02:27 am

[ephemerisle] Ripple Theater video

Here's a video of the Ripple Theater I did at Ephemerisle. Sorry for the poor video quality -- youtube's built-in compression engine does nasty things to dark parts of the image, and there's little I can do to stop it.

Funny enough, my old youtube movies are higher quality than I remember. Perhaps they kept the full-quality version of the uploaded movie on their database and later reconverted it at a higher quality level.

Time warp... we're going back to January 2006, before I really used LJ. There were kittens.

mattbell: (Default)
2009-10-08 11:30 am

Ephemerisle videos

Someone shot a video of my epic fight with Holly... my lightsaber was having some performance problems. :-)

Also, drunk guy crosses back from the Achievement Lounge after having a couple of beers:

mattbell: (Default)
2009-07-27 12:36 am
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City museum video

[ profile] radven  and [ profile] serolynne  did a nice entry on the City Museum in St Louis, including video footage of me crawling around and being generally silly.

Read more here.

mattbell: (Default)
2009-03-04 10:37 pm
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I've seen a milk shake, I've seen a fruit shake, but I ain't never seen an elephant shake.

The elephant handler asked if I wanted the elephant to "shake".

I said, "sure!"

Direct link in case embed fails:

It's about time I posted some rich media. At the moment I have 16gb of pictures and videos, almost none of them online.
mattbell: (Default)
2008-11-03 09:23 pm
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How to make fractals without using a computer

I've been having some fun this past weekend:


Video feedback is a well-known phenomenon.  If you hook a camera up to a TV and then point it at the TV, you get an infinite regression of images.  However, you can use the same feedback phenomenon with multiple displays to make fractals.  By displaying multiple smaller copies of what the camera sees, photographing that cluster of copies, and then repeating the process, you essentially create the self-similar structure seen in fractals.  By moving and rotating the camera and projectors, you can create a very wide variety of fractal images. 

The images seen in this video are not software-processed in any way.  The camera is plugged in directly to the projectors.  The pulsing and color shifting comes from the white balance and gain control of the camera.

In this setup, we're "computing" the fractal by using light on a wall as memory and the physical geometry of the path taken by the light into the camera and out from the projector as the processor to calculate the appropriate affine transformations.  Given that both TV cameras and video projectors were around back in the late 1940s, it's possible that someone could have done this sort of setup at the dawn of the computer age.

Digg if you like

mattbell: (Default)
2008-10-20 08:56 am
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Talking and singing inside a giant helium balloon

It's fun to breathe in helium from a balloon to talk in a high voice, but you only get to do it for one breath. However, you can breathe in an atmosphere that's 20% oxygen and 80% helium indefinitely.  (The nitrogen that makes up 80% of the atmosphere serves no function to living organisms, so it can be replaced with an inert gas like helium),  Thus, you can spend a good quarter of an hour giggling in funny high voices while sitting in a small chamber filled with this air.

A co-worker told me that scuba shops can give you a tank of compressed gases in any proportion you want... so I quickly ordered up a custom atmosphere optimized for silliness.  I made a giant airtight balloon out of a king size mattress bag, which was big enough to hold two people and the tank.

Here are the results: 

The video contains some mild language and a lot of silly voices but is otherwise SFW.


mattbell: (Default)
2008-07-20 11:35 pm
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Lazy sunday afternoons and asphyxiation

I had a little over 5 pounds of dry ice left over from yesterday's party.  If I didn't use it right away, it would just evaporate.  What to do? 

First, I tried making a vodka slushy.  If you put a bottle of vodka in the freezer, it stays liquid, but it if you use dry ice, you can freeze it.  Frozen vodka has the consistency of wet paste -- it's very slushy.  The taste of frozen vodka is so frostbitingly cold that you don't really taste the alcohol. 

Vodka slush made using dry ice

Next, I decided to dump the rest of the dry ice into a pot of boiling water.  There were several things wrong with this idea... not the least of which was the fact that I had just had two shots of vodka. 

First, the good stuff.  Here's how it looks:

And a movie:

Here's why it turned out to be a bad idea...



Wow... I should remember that for a price as low as $20, I can have all kinds of crazy once-in-a-lifetime experiences.   Actually, it was more like $5, as dry ice is $1/lb.  
mattbell: (Default)
2008-07-01 12:49 pm

Sinfrared Productions presents: Perils of Logo Design

Yes, we've been busy at work again!

Our 5th film, Perils of Logo Design, explores the darkly humorous world of the graphic designer's worst nightmare -- the faux pas. When your mistake can be printed thousands of times before it's discovered, the consequences are hard to live down.

To be more specific:

In 2008 the Office of Government Commerce (OGC) paid a design firm to redesign its logo.

The resulting logo caused quite a stir, and aroused plenty of attention from excited members of the press and various online communities. In the end, the logo design was changed again to end the controversy.

This film recreates that logo, and associated controversy, with the use of a cube of ice, a warm body, and a thermal infrared camera. In thermal infrared, the ice can be used like a paintbrush to paint text or images on warmer objects. The ice leaves a trail of chilled water, which shows up as a dark region on the thermal image.

Direct link:

Thanks go to my girlfriend for coming up with the idea to write the OGC logo as a demonstration of the ice writing technique.

Feel free to repost the video to your own blog entries if you like it.