I have an issue with how different types of graphics are rendered alone versus in combination. If I render a simple circle like so:

    Show[Graphics[{Thickness[0.01], Circle[{0, 0}, 0.8]}]]

I get a nicely rendered circle:
[![enter image description here][1]][1]

However, if I combine this with a slightly more fancy object like so:

    Show[Graphics[{Thickness[0.01], Circle[{0, 0}, 0.8]}], 
     ParametricPlot[{Cos[t], Sin[t]}, {t, 0, 2 Pi}, 
      PlotStyle -> Directive[Thickness[0.01]], Axes -> False, 
      Frame -> False, ColorFunctionScaling -> False, 
      ColorFunction -> (Hue[0.1184738955823293, 
          0.9378531073446328, ((1. - Sin[#3 + Pi])/2.)^0.7] &)]]

   I get this:
[![enter image description here][2]][2]

in other words, some fairly crudely rendered, pixelated objects.
How can I fix this?

P.S.: I have found a reference to a similar issue [here][3] which is somewhat disheartening. If this issue still exists (the post I just referenced is almost ten years old) then we may be out of luck: Use of `Colorfunction` may ruin rendering quality of all graphics nearby.


  [1]: https://i.sstatic.net/iTb42.png
  [2]: https://i.sstatic.net/c166R.png
  [3]: https://groups.google.com/forum/#!topic/comp.soft-sys.math.mathematica/qVbY7uQfiSM