Dot shadows

[shaunlebron]

When light is projected onto the keypoint dots, it can disrupt their detection, causing the program to disappear.

Dynamicland has recently fixed this by projecting shadows (black circles) over each dot to prevent interference from the projector light:

I'm thinking just a single supporter canvas will draw black circles over each detected point—with a high z-index to appear above all other canvases.

[ajbouh]

I've been thinking about the projector/camera interference problem and it's occurred to me that perhaps we can use polarizing filters to solve the problem.

If we polarize the light coming out of the projector in a particular way, we can filter out light with that polarization before it gets to the camera. This is essentially the same way that 3d glasses work. We may even be able to use the same polarization filters used in 3d glasses.

Apologies if this is too off-topic!

[janpaul123]

Oh I like the dot shadow idea a lot!!

polarizing filters

Unfortunately when light bounces off paper, it scatters with random polarisations again. I think in movie theatres they use super expensive special material that keeps the polarisation (might be worth checking if we could use that material though).