It’s only “Hackday Eve,” and already we’ve got a really interesting project. Michael Schieben in Hamburg has started experimenting, using the table to mix colors. Here’s a test video:

Fritzcrate Project / RGB Color Mixer from Michael Schieben on Vimeo.

And you can follow his project on his noisepages blog-in-progress (as always, apologies for the dust with noisepages – we’re making progress and should be making announcements about that soon):

http://fritzcrate.noisepages.com/

Lastly, we’ve got some tips from Adam Kumpf, co-creator of Trackmate, on calibration. First, in response to someone who wasn’t getting effective tracking at all:

A couple of thoughts. First of all, make sure the X,Y sizes match the sheet you are calibrating with (for example, if you use the 4"x4" sheet, set the X,Y to 4,4 respectively).  Also, tags are only sensed when in one of the "debug" views or the "fast mode" view.  Finally, make sure your camera is not wildly over-saturated or dark, and then do the white illumination correction by playing a white sheet of paper on the surface and pressing the "w" key.

And second, regarding a question about calibration:

Calibrate the table to the final size you want.  You don’t have to use tags, just make sure it is indeed a rectangle (for example, your surface could be 9.5"x4.5", that would be fine).  Click the corners so that it will be flattened correctly and make sure to set the X,Y size to match the size of your input surface (9.5,4.5 in this example).  Then, you can place a sheet of tags on the surface to test how it is working.  Make sure you are in one of the "debug" views or the "fast mode" view to sense tags (the other views are for setup and don’t try to find tags in the scene).  Ideally, once things are setup, you can save the settings and then never need to move the camera.  I’ve found that I don’t need to resort to fiddling when things are setup correctly (you shouldn’t need to adjust thresholds much unless you are in very strange conditions).

Obviously, you’ll want to hang out on IRC tomorrow – FreeNode #cdmblogs – and watch the stream and blog, or follow folks on Twitter, and we’ll all be sharing tips and tribulations. We’ll also debrief after the event. Should be a good chance to share some knowledge.