> with(plots):
> n:=5;colorlist:=[`red`,`coral`,`yellow`,`green`,`cyan`,`blue`,`navy`,`
> violet`,`gold`,`magenta`,`gray`,`aquamarine`,`black`,`blue`,`navy`,`co
> ral`,`cyan`,`brown`,`gold`,`green`,`gray`,`grey`,`khaki`,`magenta`,`ma
> roon`,`orange`,`pink`,`plum`,`red`,`sienna`,`turquoise`,`violet`,`whea
> t`,`yellow`,`tan`];
# Generate a unch of triangles.
> display([seq(polygonplot([[cos(n),sin(n)],[cos(n+1),sin(n+2)],[cos(n+2
> ),sin(n+3)]],color=colorlist[n]),n=1..12)]);
# Three triangles that intersect.
> Obje:={[[1,2,3],[2,3,4],[1,4,1],`red`],[[2,1,3],[2,3,1],[5,4,1],`green
> `],[[1,-1,3],[5,3,1],[2,4,1],`blue`]};
> display3d({seq(polygonplot3d([Obje[j][1],Obje[j][2],Obje[j][3]],color=
> Obje[j][4]),j=1..3)},axes=normal);
# 
# Three triangles for which in some views, the first overlaps the second
# overlaps the third overlaps the first.
> Obje:={[[4,5,0],[4,1,0],[-3,-4,4],`red`],[[6,-4,0],[4,-6,0],[-5,6,2],`
> green`],[[-3,1,0],[-2,5,0],[6,4,2],`blue`]};
> display3d({seq(polygonplot3d([Obje[j][1],Obje[j][2],Obje[j][3]],
> color=Obje[j][4]),j=1..3)},axes=normal,scaling=constrained);
# 
# 
# 
# A complicated house. Maple's 3d viewer.
> 
> house:= [ [[[1,1,0],[1,1,3],[6,1,3],[6,1,0]],`coral`],
> [[[1,1,0],[1,1,3],[1,9,3],[1,9,0]],`brown`],
> [[[6,1,0],[6,1,3],[6,9,3],[6,9,0]],`tan`],
> [[[1,9,0],[1,9,3],[6,9,3],[6,9,0]],`orange`],
> [[[0,0,3],[0,10,3],[3.5,10,5],[3.5,0,5]],`green`],
> [[[7,0,3],[7,10,3],[3.5,10,5],[3.5,0,5]],`cyan`],
> [[[3,9.1,0],[5,9.1,0],[5,9.1,7],[3,9.1,7]],`yellow`],
> [[[3,10.2,0],[5,10.2,0],[5,10.2,7],[3,10.2,7]],`red`],
> [[[3,9.1,0],[3,10.2,0],[3,10.2,7],[3,9.1,7]],`maroon`],
> [[[5,9.1,0],[5,10.2,0],[5,10.2,7],[5,9.1,7]],`magenta`],
> [[[4.9,9.2,6],[4.9,10.1,6],[3.1,10.1,6],[3.1,9.2,6]],`black`],
> [[[0,.1,3],[7,.1,3],[3.5,.11,5]],`wheat`],
> [[[0,9.9,3],[7,9.9,3],[3.5,9.9,5]],`plum`],
> [[[2,.9,0],[2,.9,2],[3,.9,2],[3,.9,0]],`gold`],
> [[[0,.1,3],[0,9.9,3],[7,9.9,3]],`violet`],
> [[[7,9.9,3],[0,.1,3],[7,.1,3]],`blue`]];
> n:=nops(house);
> display3d([seq( polygonplot3d( house[j][1], color=house[j][2]),
> j=1..n)],axes=normal,scaling=constrained,projection=0.7);
# 
# 
# 
# A simple house. This one we'll draw often.
> house:= [ [[[0,0,0],[0,0,3],[3.5,0,5], [7,0,3],[7,0,0]],`coral`],
> [[[0,0,0],[0,0,3],[0,9,3],[0,9,0]],`brown`],
> [[[7,0,0],[7,0,3],[7,9,3],[7,9,0]],`tan`],
> [[[0,9,0],[0,9,3],[3.5,9,5], [7,9,3],[7,9,0]],`orange`],
> [[[0,0,3],[0,9,3],[3.5,9,5],[3.5,0,5]],`green`],
> [[[7,0,3],[7,9,3],[3.5,9,5],[3.5,0,5]],`cyan`],
> [[[3,9.1,0],[5,9.1,0],[5,9.1,8],[3,9.1,8]],`yellow`],
> [[[3,10.2,0],[5,10.2,0],[5,10.2,8],[3,10.2,8]],`red`],
> [[[3,9.1,0],[3,10.2,0],[3,10.2,8],[3,9.1,8]],`maroon`],
> [[[5,9.1,0],[5,10.2,0],[5,10.2,8],[5,9.1,8]],`magenta`]];
> n:=nops(house);
> display3d([seq( polygonplot3d( house[j][1], color=house[j][2]),
> j=1..n)],axes=normal,scaling=constrained,projection=0.7);
>