section s of routines in pl3d.i

functions in pl3d.i - s

save3


    view= save3()  


Save the current 3D viewing transformation and lighting.  
Interpreted function, defined at i/pl3d.i   line 233

SEE ALSO: restore3, rot3, mov3, aim3, light3

set3_object


    set3_object, drawing_function, _lst(arg1,arg2,...)  


set up to trigger a call to draw3, adding a call to the  
3D display list of the form:  
   DRAWING_FUNCTION, _lst(ARG1, ARG2, ...)  
When draw3 calls DRAWING_FUNCTION, the external variable _draw3  
will be non-zero, so DRAWING_FUNCTION can be written like this:  
func drawing_function(arg1,arg2,...)  
{  
  require, "pl3d.i";  
  if (_draw3) {  
    list= arg1;  
    arg1= _nxt(list);  
    arg2= _nxt(list);  
    ...  
    ......  
    ......  
    return;  
  }  
  ......  
  ......  
  set3_object, drawing_function, _lst(arg1,arg2,...);  
}  
Interpreted function, defined at i/pl3d.i   line 630

SEE ALSO: get3_xy, get3_light, sort3d

setz3


    setz3, zc  


Set the camera position to z=ZC (x=y=0) in the viewer's coordinate  
system.  If ZC is nil, set the camera to infinity (default).  
Interpreted function, defined at i/pl3d.i   line 113

SEE ALSO: rot3, orient3, undo3, save3, restore3, light3

sort3d


    sort3d(z, npolys, &list, &vlist)  


given Z and NPOLYS, with numberof(Z)==sum(npolys), return  
LIST and VLIST such that Z(VLIST) and NPOLYS(LIST) are  
sorted from smallest average Z to largest average Z, where  
the averages are taken over the clusters of length NPOLYS.  
Within each cluster (polygon), the cyclic order of Z(VLIST)  
remains unchanged, but the absolute order may change.  
This sorting order produces correct or nearly correct order  
for a plfp command to make a plot involving hidden or partially  
hidden surfaces in three dimensions.  It works best when the  
polys form a set of disjoint closed, convex surfaces, and when  
the surface normal changes only very little between neighboring  
polys.  (If the latter condition holds, then even if sort3d  
mis-orders two neighboring polys, their colors will be very  
nearly the same, and the mistake won't be noticeable.)  A truly  
correct 3D sorting routine is impossible, since there may be no  
rendering order which produces correct surface hiding (some polys  
may need to be split into pieces in order to do that).  There  
are more nearly correct algorithms than this, but they are much  
slower.  
Interpreted function, defined at i/pl3d.i   line 880