I would have put “true 3D” in quotes in the title, but that’s not actually possible with my blogging software, so take that with a grain of salt. What I’m referencing is a great analysis of “true 3D” vs. “pseudo-3D” as put forth by Oliver Kreylos, a professor at the University of California-Davis, who’s interviewed in this MachineDesign.com article by Leslie Gordon on the use of Kinect in 3D modeling.
Great piece. One of the best I’ve seen on Kinect and why it’s so exciting for 3D imaging professionals and computer programmers in that it doesn’t just try to wow with YouTube videos.
But I’m most interested in the way that Kreylos talks about 3D and I think it might be useful for those of you who find yourselves talking about 3D with asset owners or even people at cocktail parties who might be new to commercial uses of 3D and just know 3D from watching Avatar with their kids.
Kreylos calls what he’s creating with Kinect a “3D holographic image,” even though it’s not creating a hologram in any of the ways that we normally think of one. So, why “holographic”?
Here’s how he lays it out:
“The term ‘holographic’ is actually technically incorrect. But I felt I had to use it to distinguish the true 3D video coming from the Kinect from pseudo-3D stereoscopic video such as what’s shown in ‘3D’ movies such as Avatar, or captured by available ‘3D cameras.’ The difference is that pseudo-3D video can only be viewed from the point-of-view of the camera that originally recorded it, just like regular 2D video. True 3D video, on the other hand, can be viewed from any arbitrary viewpoint, even after it has been captured. It has this property in common with real holograms, hence I chose the moniker as a short-hand.”
Kreylos explains that, colloquially speaking, Jim Cameron could not go into the editing room after shooting a live-action scene in Avatar, and say, “OK that’s great, now let’s see this scene from the point-of-view of that blue guy on the right,” says Kreylos. “Although this is possible with true 3D video, a true 3D video camera is still a camera and it cannot see through or around solid objects. This means users would need multiple Kinects to pull off the full effect. For example, because a 3D camera can only create a 3D model of what it sees, a 3D holographic model of me would only shows one side of my body. We call this half-representation a ‘facade.’ Using multiple cameras would allow combining respective facades into complete 3D objects, an ongoing area of my research.”
First, I love that Leslie Gordon refers to “Jim Cameron” like they’re buddies. You know, Jim, the guy who made Avatar. That’s terrific.
But, more importantly, this guy Kreylos is essentially talking about registering point clouds, and it’s where surveyors can come in and talk about the importance of the work they do, integrating GPS, etc., to make sure that the point clouds they create have real-world references that make them valuable. This coming together of the worlds of computer programming and 3D modeling and getting excited about the possibilities of 3D imaging with the precise world of surveying and engineering is where things could get really cool and useful at the same time.
Anyway, at least when someone says at a party, “oh, I LOVED Avatar,” after you’ve told them you work in 3D, at least you have another crib sheet for explaining to them what it is you’re really after.
