LOS ANGELES — We saved Pandora. We got seasick with Pi. We danced with Gatsby, all in 3-D.

Are there any thrills left in what was supposed to be Hollywood’s medium of the future?

For some, George Clooney’s chin in Imax 3-D — digitally remastered for the large-format version of “Gravity,” due from Warner Brothers on Oct. 4 — might qualify. So it’s not over yet.

But in general, filmgoers in North America — having sampled three-dimensional viewing in films as breathtaking as “Avatar” and “Life of Pi,” — are drifting back to conventional theaters. That is happening despite an aggressive digital conversion program by exhibitors, who raised the number of domestic 3-D screens to almost 15,000 at the end of last year, more than four times the count in 2009.

This summer, films like “Turbo” and “The Wolverine” took in 30 percent or less of their opening weekend receipts from 3-D sales, compared with levels as high as 60 percent for summer films only a few years ago.