void d3line (xf, yf, zf, xt, yt, zt) D3AUX.C Level 3
 
float xf, yf, zf The location of the "from" point in user units.
float xt, yt, zt  location of the "to" point in user units.
 
d3line() draws a line from (xf, yf, zf) to (xt, yt, zt) in user units as defined by a call to graf3d().