Here are NCAA Ohio and Oregon CGI stadiums I did for NIKE ads.
Photography Marcus Eriksson http://marcuseriksson.net/
Stadiums, as previously were done with hard use of Itoo Railclone plugin http://www.itoosoft.com/railclone.php for geometry and Forrestpack http://www.itoosoft.com/forestpack.php for crowd. Rendered as always with VRay.
I created many different spark variations for exploding bulbs in Particle Flow.
Here are example of few variations:
Sample of Particle Flow view for all variations:
And here is screenshot of sparks for Oregon:
Small animation of sparks: