15.44.17  3-d_plot 

This produces a mesh plot of the data.  Essentially the  data  points  are
joined in X,Y.  If you specify color, intensity, or texture it is used for
the top side of the mesh, while the default is used for the bottom.

                                  example
     TD:SET COLOR RED
     TD:SET TEXTURE DOTS
     TD:JOIN SOLID WHITE
Produces  a  mesh plot with bottom in dotted red lines, while the top side
is drawen in white solid lines.