Americans began watching a yule log on TV in 1966, and can now see it in HD or 3-D.

It had to happen: the yule log in 3-D.

This latest refinement carries a whiff of retrofitted modernity, like a space capsule upholstered in chintz or a Microsoft Kinect game of croquet. But each generation has to find its own way to televise Christmas warmth, and a three-dimensional yule log is “Avatar” without blue people, “Saw 3D” with carols instead of bloodcurdling screams.

“Yule Log 3-D” is not convenient to view, however. This season it’s probably easier to commandeer a real fireplace — or light a sidewalk bonfire — than to find a friend or neighbor with a working 3-D TV set. (About 38 million U.S. homes have working fireplaces; and while industry projections for 3-D TV sales over the next few years are in the millions, the research firm SNL Kagan estimates that only about 400,000 sets have been bought so far.) But it does exist and it can be seen, albeit only through special 3-D glasses.

So before consumers rush out to buy a 3-D set this Christmas or next, it’s important to explore whether a television yule log is any more yule-ish or loglike with an added dimension.

To find out, I had to go to the Manhattan headquarters of In Demand Networks, which has developed a 3-D yule log. It is the logical sequel to In Demand’s Yule Log HD, which has been available on Time Warner, Comcast and several other cable providers since 2002 and which is quite pleasing.

Americans began opening presents and drinking eggnog in front of a film loop of blazing flames in 1966, back when it was in black and white. That high-concept metaphor for the television as the family hearth caught on, was refilmed in 1970 and became a kitschy Christmas tradition as beloved as Andy Williams specials or the Radio City Christmas show. DVD versions come with all kinds of fancy extra features — “Yule a Go-Go” comes with dancers performing a naughty Christmas carol striptease.

When viewed properly, the 3-D yule log is quite good, the flames vivid but not alarmingly feverish. It’s a cozy fire, not a conflagration. The background music, which can be muted, is an inoffensive offering of standards, from a jazz trio rendition of “O Tannenbaum” to a full orchestral version of “It Came Upon the Midnight Clear.”

After a while, the 3-D log is quite hypnotic. Until, of course, you turn to the person next to you and discover that you are both wearing dark glasses indoors, and then the spell is broken.