A method to sync the lip and facial movements of animated characters in video games is eligible for patent protection, a U.S. appeals court ruled Tuesday in a case closely watched by the video-gaming and software communities.

McRo Inc., also known as Planet Blue, had sued about two dozen gaming companies over claims they used patented methods to automatically animate lip movements and facial expressions. A trial judge said the ideas were abstract and thus not eligible for a patent.

The case put the gaming industry in a bind — it wanted to avoid the McRo suit but feared the ramifications of losing legal protection for their own software.

The U.S. Court of Appeals for the Federal Circuit said the trial judge erred in saying the McRo inventions were nothing more than using a computer on a conventional idea. It remanded the case for further proceedings to allow McRo pursues its claims.

Among the gaming companies that were sued were Electronic Arts Inc., Walt Disney Co.’s Disney Interactive Studios and LucasArts, Activision Blizzard Inc. and Sony Corp.’s Computer Entertainment unit. They will have to make other arguments if they want to avoid paying royalties to McRo.

The gaming companies had argued that McCro’s patent sought to claim “a concept that is inherent in human speech — that a human mouth will look a certain way when speaking a certain sound.”

The three-judge Federal Circuit disagreed, saying the patent claims are “limited to a specific process for automatically animating characters using particular information and techniques and does not preempt approaches that use rules of a different structure or different techniques.”

The techniques were developed by Planet Blue’s award-winning founder Maury Rosenfeld. McRo said Rosenfeld’s work was hailed as “revolutionary” and he did animation projects for many of the companies before he sued them for using the techniques on their own without permission.

McRo’s legal arguments were supported by BSA-The Software Alliance, a Washington trade group that includes Microsoft Corp. and Oracle Corp. as members. The group has criticized the interpretation of a Supreme Court ruling that has resulted in hundreds of software patents being invalidated.

Public Knowledge, a Washington-based policy group, argued that the McRo patents are invalid, and more broadly that software patents are too often used to stunt industry growth rather than promote it, as patents are supposed to do.