After failing to correctly remember some vector/angle conversion formula and going back to re-read my own lecture slides (this happens all the time...) I decided that it was time to write a look-up cheat sheet for these things;
A set of commonly used 3d maths and linear algebra formulae for those like me - with a brain that tends to delete this stuff from memory immediately. Click image for .pdf.
3d camera vis
I have to switch back to working on buildings again soon, so my tie-it-up plan for the 3d camera visualisation is:
switch from 2d particles to 3d meshes (or maybe resize the particles with z) for the faces so that you can see the depth
detect nods (y) and shakes (x) of heads and derive the frequency and amplitude. then I can say "if f > some threshold then head is nodding 'Yes'".
print out these tracking stats either in text or with some sort of real-time graph
clean up the camera feed and track the face positions so that the characters are never mixed up
write up a technical report as a workshop style "this is how you visualise 3d data with webgl, and this is how hard it is to do" sort of thing.