In case you didn’t watch comments on my Pixel Bender preview, there was some good discussion, including Kevin Goldsmith, who manages the Adobe Image Foundation group; he blogs at digital-motion.net and specifically on these technologies at blogs.adobe.com (and he’s a musician, too).

I overstated the importance of Pixel Bender being GPU accelerated. First off, of course, you really don’t care where code executes, whether on the CPU or GPU – you care about whether it’s fast, and whether it does what you need. In this case, different CS4 tools accomplish that differently:

• After Effects CS4: GPU-accelerated
• Photoshop CS4: GPU-accelerated (as is the new pan/rotate/zoom feature, as I indicated)
• Flash 10 (in CS4 Suites): CPU, multi-threaded

So, it was effectively the Flash answer I got wrong. That’s not to say Flash doesn’t use the GPU; it accelerates some drawing routines with the GPU (as, incidentally, Java and by extension Processing have done in the past, even in 2D).

Tinic Uro, an engineer on the Flash team, explains that the reason is compatibility:

Running filters on a GPU has a number of critical limitation. If we would have supported the GPU to render filters in this release we would have had to fall back to software in many cases. Even if you have the right hardware.

If you haven’t seen it yet, Jamie and Adam did what may be the greatest illustration of a computing concept onstage ever, using an 1100-barrel paintball gun:

Updated: We’ve seen the basic idea before — one of the Max/MSP + Atmel-powered Printball notes his own, similar project, as featured on Pixelsumo way back in 2005. But it’s the first time I’ve seen this used to illustrate this point.

The basic idea: GPUs, by using parallel processing, are able to render graphics more effectively than CPUs. And while the illustration is something of an oversimplification, it is pretty literal in terms of showing people what’s going on — and why GPUs are uniquely well-suited to computing graphics. Conceptually, it’s really one of the most brilliant demos I’ve ever seen.

There are just a couple of problems — and, amusingly, this demo makes them visible, as well.

CDMo reader Memo writes:

I’m just rushing out the door off to Glastonbury to set things up.. I thought you might be interested in this little (!) project…

Glastonbury 2008 PI Teaser (Webcam Piano + Psychedelic Fluids) from Memo Akten on Vimeo.

Everything is entirely camera driven and realtime. Originally started this app in processing, but realized I needed as much power as possible so switched to C++ / OpenFrameworks. Not using the GPU as much as I’d liked due to time restraints, v2 will be fully GPU hopefully ;)

Anyone going to Glastonbury? Drop in and play Memo’s piano for us. Working on your own (little!) project? Contact form’s to the right.