Another in a series: vimeo.com/album/1505429
10 particles move around linearly at various constant speeds, bouncing off the sides.
For each pixel, calculate the distance from the pixel to each particle. Sort these distances to get d_1, d_2, ..., d_n. Find k such that z=| d_1+d_2+...+d_k - (d_k+1+...+d_n)| is as small as possible. Color the pixel according to this minimal z value.