Patent No. US 6,326,972

Around 1996, I was working on Antz, the first feature film produced by PDI and DreamWorks.
I was in charge (among other things) of the crowd system with Juan Buhler and Jonathan Gibbs.
Back in the days a crowd scene of several thousand ants was pretty much unheard of and we had a whole movie full of them.
The opening scene of the movie and also a critical scene in our first trailer, was a crowd scene with several thousand characters. Rendering them in a traditional brute force way was impossible for the hardware and software of those days.
One morning I realized that I could use the in-house particle render to draw small strokes representing the segments of an ant. Instead of telling the render about the past, present and future position of a particle, I would describe the shoulder, elbow and wrist position for example, and the renderer would very quickly create something reasonable if rendered small on screen.
I quickly put together a test comparing the traditional geometry render against the output of the particle system. My fellow TD did not see the difference when the character was 20 pixel height. The difference in rendering time was incredible.
We quickly decided to test the technique on a bigger scale. Juan and R+D designed a nice interface to feed the particle render the proper data. I modified the character setup to output the correct joint location.
The opening scene for Antz was born just in time for the trailer, hundred of scenes in the movie benefited from the novel technique and a patent was later filed.