Playing with light: "Hologram" (Pepper's Ghost) projector

There's a neat trick you can do with angled plastic to give the impression of an image floating in space. While this is technically a "Pepper's Ghost" illusion, it commonly goes online by the name "Pyramid Hologram." For our friends at Iguanatron, we put together a top-down projector implementation with a 20" computer monitor.

So here's how it went down.

GoBlockly Interpreter: An Interpreter for Blockly in Go

I've just published GoBlockly: an interpreter for the Blockly visual editor output written in Go. This is something I wrote as part of a larger project (reimplementing the Belphanior Butler in Go), but it was a reasonable-sized chunk to break off and polish. It passes Blockly's own unit tests and allows for addition of custom blocks.

Example output of a server running GoBlockly library

If you program in go and want to play around with Blockly as a UI for simple code authoring, feel free to try it out! It doesn't come batteries-included (i.e. you'll need to set up your own Blockly web client and send the code back-and-forth to the server in go), but Go makes it easy enough to write a web server that this should be straightforward.

Have fun! :)

Cecilia's Drawing Toy: Updated for Little Hands

You learn a lot about proper software design by actually watching users. This is a well-known fact, but sometimes a reminder is helpful.

Cecilia was in town for several weeks, so I got a chance to watch her playing with her drawing toy. I noticed that she preferred to hold the phone tightly with one thumb, which really threw off the motion tracking.

A few changes later, I added support for multiple-touch operations. If little hands need to grab the screen in two places, that's not a problem!

It's also good for finger-painting. :)

As always, the updated version is available on the Play Store if you're not in the mood to mess around with compiling your own.

Intro video for Nausicaa

I completed an intro video for Nausicaa, my Google Glass telemetry view for Kerbal Space Program (using the Telemachus plugin). Check it out!

Halloween Costume: Jebediah Kerman

So, you might say I've been playing a lot of Kerbal Space Program recently. So with Halloween rolling around, I thought to myself: Why not make a costume of the web's favorite fictional space explorer?

Cecilia's Drawing Toy: now with eraser

Made a few tweaks to Cecilia's Drawing Toy today:

• I learned that the gravity sensor is actually a lot more rare than I'd anticipated, so I tuned the code to use but not rely on either the gravity or accelerometer sensors (when they're missing, you don't get "hold upside down and shake to erase," but the toy still works). Toy is now usable on an additional 4,000-some-odd devices.
• Since users without shake-to-erase would be lacking an erase option, I added a good old-fashioned eraser tool. Additional tools (paint bucket, undo, multiple layers with arithmetic overlay masking transform blending using Porter-Duff algorithms) to be added in subsequent releases, on an undisclosed, indeterminate, and really quite imaginary schedule.

Cecilia and her family are actually in town, so I got a chance to see her try it out. She did good; that's a quality "F" in there! Not bad for a 1-year-old.

Tablets in the wild

You learn some interesting things as an Android developer.

Periodically, I check up on my crash reports to verify that there isn't anything crazy going on with my app. Today, I was sad to see that I'm getting crashes on machines with no gravity sensor—my mistake; need to push a fix.

The list of machines, though, was interesting. One of the devices that showed up was a "nuclear-86v2g", which I had not heard of before. Some Googling turned up the details: it's apparently a not-well-known (in the States, anyway) Chinese tablet by the name of "Amaway," which runs Android 4.0. Sadly, it appears to lack a gyroscope sensor and so won't run Cece's toy, but it's interesting to see how far a simple program can travel on the web.

Cute little thing (image source)