The vfx artists were able to control the actions of various crowd members.

They could also cheat people even if the angle dictated that they were looking, say, in the outfield. They could take 50% of the people at 90% that look like they're looking at the action that's happening right by camera. Rhythm & Hughes used its in-house tracking software and rendered it in mantra and then composited also using its Icy in-house software.

Thus, the overall significance of this system allowed helmer Bennett Miller to direct the crowd: A little more cheering here; more people standing up; make it little sparser as you get closer to the outfield and denser at it gets to home plate. They had total control. "

However, there were lighting challenges, as you might expect with Oscar-winning cinematographer Wally Pfister (Inception) shooting Moneyball, so Rhythm & Hues had to come up with a lighting system as well.

"He lit the stadium much differently than you would normally see a stadium," Rivera admits. "Usually at night you're lit pretty much everywhere, but he lit it much more stylistically where one side was completely lit and the other side was completely dark. So on any given shot that could change based upon where the camera was or based upon how he changed his lighting. We not only had to create people that would work for the different angles, but we also had to create lighting for every angle. So, using Houdini, we wrote a shader that, based upon the light distance and intensity, we were able to create a matte offset for the 2.5D people.

"Let's say that we had a huge bank of lights at 45 degrees to the screen right of the character. The matte offset would then scoot the matte down and to the left ever so slightly so we had a rim matte that the compositors would then use to keep the original lighting or brighten up the 2.5D people."

This also worked for daytime shots, allowing them to, "Play ball," in as a believable a manner as possible.

Bill Desowitz is former senior editor of AWN and editor of VFXWorld. He has a new blog, Immersed in Movies (www.billdesowitz.com), and is currently writing a book about the evolution of James Bond from Connery to Craig, scheduled for publication next year, which is the 50th anniversary of the franchise.