NEW YORK (AP) — ESPN’s decision to shut down its 3-D channel by the end of the year is the latest sign the format won’t revolutionize entertainment as the industry once hoped.

Troubling signs for 3-D have been on the horizon for the last year or so. ESPN 3D’s audience ratings were below The Nielsen Co.’s measurable threshold, and in March, the Motion Picture Association said box office revenue for 3-D showings in the U.S. and Canada held steady at $1.8 billion in 2012. The number of 3-D films released in the period dropped by 20 percent.