Attached is a file I made about a year and a half ago for a lightpainting project..just wave a cellphone or an led in front of it..it only draws with the brightest parts of the image. It taught me a lot about different kinds of image processing with matrices and how to combine them to make interesting effects. I’d love to be able to copy this into an opengl environment, but a lot of the temporal blurring that makes this such a nice effect are very difficult to achieve. Maybe sometime in the future though…I’ve attempted it, but the temporal blurring is much less gradual..especially when I clear the drawing. Would be nice to get this up to at least 640×480 at 30fps though…too many jit.repos’s in the chain though.
If anyone wants me to explain the signal chain I’d be happy to. Or if anyone has suggestions for improvement, hit me up.
Cool cool! This needs to be at Burning Man so the million LED blinkies that everyone’s wearing can be in the video…and the fire spinners… not to mention projecting it onto some really really big screens, all to some great beats from huge sound systems…
About the GL stuff, have you tried setting the erase_color to black and a very low alpha, like
erase_color 0. 0. 0. 0.001 ?
That’s worked wonders for fades and trails in GL for me.
I was feeling generous today and spruced up another example of mine that I had posted above. The one posted on my site has better comments and some example image to give you a better idea of the image processing flow: