A normal modifier can do an excellent job.
For example, the floor in the following image is just a plane:
http://www.cs.tut.fi/~warp/tnt/Detonaattori.jpg
--
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/
