functions in pl3d.i - a

    aim3, xa,ya,za  


move the current 3D plot to put the point (XA,YA,ZA) in object  
coordinates at the point (0,0,0) -- the aim point -- in the  
viewer's coordinates.  If any of XA, YA, or ZA is nil, it defaults  
to zero.  
Interpreted function, defined at i/pl3d.i   line 98