Geometry in OpenGL is not rendered anti-aliased and this is why
you're observing "jaggies". You could however render the cube in a
Render in Image patch and then display the resulting image scaled
down
This didn't work for me. When I did this, it rendered all wacky. My
animations "smeared" and the cube faces didn't show up, only the
images I
had composited on those faces.
Add a Clear patch to the inside of the Render in Image patch
