A sneak preview of scenes from DreamWorks Animation’s 2009 release Monsters vs. Aliens was met with riotous applause at ShoWest on Tuesday. Studio chief Jeffrey Katzenberg presented the footage from the kiddie flick, which stars the voices of Reese Witherspoon, Seth Rogen, Will Arnett, and Stephen Colbert (as the President of the United States, of course), and he couldn’t have expected a better reception. After all, in recent years at ShoWest, movie industry insiders have spent a lot of time predicting a coming 3-D revolution, but it has yet to arrive. So why was this presentation so successful? Credit a process that DreamWorks Animation has dubbed “Ultimate 3-D,” which has the effect of bringing the viewer into the world of the movie, rather than having stuff pop off the screen. (Really, you have to see it to believe it.) Also key: Monsters vs. Aliens is the first movie to be completely made with 3-D software, as opposed to its predecessors, which were converted to 3-D only in postproduction. No wonder Katzenberg has been lobbying theater chains to put in more digital screens for 3-D.