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