The technical issues seem resolved, but what about the artistic?
From my personal notions of what makes a good rendering after seeing dozens of images like your posted on Archicad Talk:
-- What are we really looking at here that makes us want to be there, or should we just flee between the buildings over to that inviting bosk of trees?
-- Can you recompose the view to contain and beguile the eye? Perhaps to lead the eye obviously to the entrance of the building, or make the play area the focus of the shot by placing it in the foreground, with buildings as a mere background to happy play. Make up a story.
-- Another thing: Those white walls. Perhaps changing the sun angle will make them glare less, or simply turning down their reflectance ever so slightly. They will still look white but not overpowering.
-- And the last thing: lose that geezer on the left scoping the kid. Bad juju.
Dwight Atkinson