% --- start of displayed preamble in the book --- input featpost3Dplus2D % --- end of displayed preamble in the book --- defaultfont:="ptmr8r"; warningcheck:=0; beginfig(1) Spread := 30; f := 5.4*(1.5,0.5,1); numeric gridstep, sidenumber, i, j, coord, aa, ab, ac; color pa; gridstep = 0.7; sidenumber = 4; coord = 0.5*sidenumber*gridstep; for i=0 upto sidenumber: for j=0 upto sidenumber: pa := (-coord+j*gridstep,-coord+i*gridstep,0); aa := uniformdeviate(360); ab := uniformdeviate(180); ac := uniformdeviate(90); kindofcube(false, false, pa, aa, ab, ac, 0.4, 0.4, 0.9 ); endfor; endfor; endfig; end;