pfTransparency works only on machines that support either
  blendfunction or multisampling.

  Sometimes users report that their transparency seems quantized.  This
  is not a bug -- Performer defaults to using Multisample transparency
  (msalpha) when multisampling is enabled, instead of using the
  "standard" (blendfunction) transparency mechanism.

  Multisample transparency is faster but has much less resolution, and
  so less quality.  Standard transparency using blendfunction is
  slower, but the quality is very good.

  To force Performer to use higher-quality (but slower) transparency
  when multisampling,

  1.0/1.1:  pfGStateMode (gstate, PFSTATE_TRANSPARENCY, 2);
  1.2/2.0:  pfGStateMode (gstate, PFSTATE_TRANSPARENCY, PFTR_HIGH_QUALITY);
                                                    aka PFTR_BLEND_ALPHA

  In 1.0/1.1 the BLEND_ALPHA token was not exposed, but just use '2'.
  Be sure to revisit this code when you port to 1.2, as the token has
  changed.

  See the pfTransparency(3pf) man page for more details.