FYI: What's with the resurgence of 3D films and how do they differ from the old ones?

After years in the film-industry doghouse, 3D (the illusion of depth seen by the viewer) is back with a vengeance. Paramount Pictures' decision to bring Beowulf director Robert Zemeckis' animated take on the old English epic poem to 3D as well as regular movie screens was seen as something of a gamble. After all, this is a technology that reached its most recent peak with a spate of poorly performing sequels in the 1980s - witness Jaws 3-D and Amityville 3-D - that many studios would rather forget.

But Paramount's wager has paid off. More than 40 per cent of the US$28 million in revenue Beowulf scooped up in its opening weekend in the United States came from 3D ticket sales, even though 3D screens account for only 20 per cent of the total number of screens.

Given Beowulf's success, the trickle of 3D films now on offer is expected to turn into a torrent. A number of high-profile projects, including Avatar, a sci-fi opus from Titanic director James Cameron, and a Steven Spielberg-backed version of the adventures of Belgian comic-book hero Tintin, are already in production.

The extra dimension has received additional credibility with animation giant Dreamworks' recent pledge that all its releases from 2009 onwards will be in 3D.

This may sound eerily familiar to readers old enough to remember the format's earlier incarnations - shoddy red and blue glasses and all - but the technology has moved on.

In 2005, Disney's Chicken Little became the first film released in the digital 3D (or Real D, the name of the technology used and its main corporate backer) format, which looks set to become the next industry norm.