It's Jiri Trnka, actually--the last name has only one vowel, the A, but is pronounced "Trinka," i believe.

I sometimes confuse his shorts with Zeman's earlier stuff, like INSPIRATION. One of these guys did a stop motion short featuring glass figurines. Between frames, their joints were heated until they softened, then moved. When they cooled enough another frame was shot. In the film, you can see the joints occasionally glow a faint cherry red.