The compositing of the CG elements with the live action was done with R&H's proprietary tool Icy. The studio's multi-pass rendering approach permits a lot of flexibility during the compositing process. 

Shifflett credits the attention to detail that the compositors lavished on Alvin and the Chipmunks. "We had some compositors going off and shooting their own elements because they wanted to add something extra to a scene. It's great when people get that excited about the work."

"The biggest challenge on these projects is more the schedule than anything else," Shifflett admits. "Putting together a pipeline that runs smoothly without hiccups is an art form in itself."

One thing that didn't turn out to be problematic for Shifflett was having to listen to the chipmunks' high-pitched voices repeatedly singing their famous tune. "When we first got the assignment I thought, 'I don't think I can take listening to those voices as much as we're going to have to listen to them.' When I was little, I had the Chipmunks' punk album, though I didn't go and dig it out. But, oddly, it wasn't as bad as I thought it was going to be. They were very funny, appealing characters and I was amazed at how everybody responded when they watched these guys." But Shifflett does admit, "Those songs are still rattling around in my head. It will take a while to get them out of my system!"

Ellen Wolff is a southern California-based writer whose articles have appeared in other publications, including Daily Variety, Millimeter, Animation Magazine, Video Systems and the website CreativePlanet.com. Her areas of special interest are computer animation and digital visual effects.