An animation by Alex Zhao for the "DoomGate" website, created in March 1995 and rendered on an SGI Indy using Alias Studio.
The original version is still online (!) at http://www.cc.gatech.edu/gvu/people/qiang.a.zhao/Media.html#DoomAnim
Original description: "The title is called DoomGate (inspired by the real DoomGate). It has 600 320 by 240 frames. I designed and created the animation - I'm not a good animator yet, and somehow the MPEG movie has some strange things in it (maybe I chose a bad parameter to the encoder or something) - so don't expect too much :-)."