Hi Brian,

i found from Steven An the tetrus as .stl file :-)

http://www.google.de/imgres?num=10&hl=de&biw=1129&bih=999&tbm=isch&tbnid=zh_Y5h_rq6KjsM:&imgrefurl=http://www.cs.berkeley.edu/~sequin/CS285/LECT06/L30.htm&docid=7XHdnsFbEMzgeM&imgurl=http://www.cs.berkeley.edu/~sequin/CS285/PROJ_06/Steven_An/Steve_TetrusTex.jpg&w=341&h=300&ei=8Q5cUPLFNNHXsgaVkoDoBA&zoom=1&iact=hc&vpx=490&vpy=419&dur=2896&hovh=211&hovw=239&tx=137&ty=117&sig=114515771111061153651&page=2&tbnh=141&tbnw=188&start=31&ndsp=32&ved=1t:429,r:2,s:31,i:182

click on the left image (10:20: Steven An) and in the directory click "steven-txs-pkg" directory.

Looks quite different than what i thought...

Best regards
Stefan