Many thanks to Mark Kriegsman as usual. Got the inspiration for this from his anti-aliased light bar example (http://pastebin.com/g8Bxi6zW). I first extended into a 2D matrix to figure out how to light 4 pixels and then went to 3D in my L3D Cube.Two virtual pixels in a 3D environment. There are 16 fractional locations between each physical pixel so when the pixel is not exactly located on a physical pixel, up to 8 pixels will light proportionately to the location of the virtual pixel. This demo uses just 2 virtual pixels. I purposely made one fast and one slow hence the title.
Once I got that working, I jumped to enable multi-pixels. Now the code supports any number of pixels chasing each other around in the cube. Tons of fun! Best toy I've bought in years.
Video:
https://www.youtube.com/watch?v=O-fDF_HVPtICode: http://pastebin.com/mNHaKHg3