[burchard: mgri weirdness, or maybe mggettransform() weirdness?]

[munzner]

Something peculiar occasionally happens to me in oogldemo: the edges  
of a polyhedral Geom are rendered as if with a different (typically  
degenerate) transform than the faces.  The faces are drawn correctly,  
but the entire skin of edges has been peeled off the object,  
typically being collapsed into a plane (perhaps always the X-Z  
plane?).  Has this ever been seen before?

I haven't been able to reproduce this problem with the NeXT version  
of Geomview, even the recent compiled version Geomview12-30.app which  
Stuart pointed me toward.

Could it be that I am calling the MG library in a sequence which is  
not guaranteed to be reliable?  Or, more likely, could it be that  
mggettransform() is unreliable?  (It's the one MG call I'm making  
that isn't used in any essential way in Geomview.)  So that you can  
easily check my usage of MG, I've extracted an outline of all the MG  
calls I make:

  /* setup */
  mgContext = mgctxcreate(
    MG_BACKGROUND, &backColor,
    MG_ZNUDGE, 3.E-5,
    MG_CAMERA, mgCamera,
    MG_APPEAR, mgAppearance,
    MG_WnSet, WN_XSIZE, frame.width, WN_YSIZE, frame.height, WN_END,
    MG_END);
  mgreshapeviewport();
  mgctxselect(mgContext);
  mgworldbegin();

  /* draw main geom */
  GeomDraw(worldGeom);

  /* draw auxiliary geom */
  mggettransform(T);
  DO_SOMETHING_WITH(T);
  mgpushtransform();
  mgtransform(T);
  GeomDraw(auxGeom);
  mgpoptransform();

  /* shut down */
  mgworldend();
  mgctxdelete(mgContext);