3.5D

Let’s back down half a dimension from yesterday’s post and talk about 3.5D. What, you may well ask, is 3.5D? Actually it’s a term I made up, but it refers to something very specific.

This evening I went out to the movies to see one of the big science fiction flicks currently on offer. It was filled with great computer graphics, and thrilling action scenes.

I had made the deliberate choice to see it in 2D, even though I could have seen it in 3D. The reason? 3D in movies, the way that term is currently defined, is highly problematic.

In real life, when you are sitting across a table from somebody you’re talking to, and you move your head — even a little — the entire room behind your conversant appears to move. This is simply motion parallax: When you move your head from side to side, nearby things appear to shift by a greater amount than far away things.

But in a 3D movie nearby and far away things move together when you move your head. In fact, they always move together.

In my case, this takes me clear out of the movie. All I can think about in such moments are the deficiencies of today’s stereo 3D movies, and those thoughts take away from my enjoyment of the film.

In contrast, the collective VR technique our lab is developing for immersive cinema solves this problem. Just as in real life, when you move your head from side to side, near things appear to shift more than far away things do.

I call that 3.5D. And I’m sticking with the name until somebody comes up with a better name.

One thought on “3.5D”

  1. When I was a member of the NSA (that’s the National Stereoscopic Association), a lot of the members would deride people who spoke about 3D graphics. Sure, the models are 3D, but the rendering process projects everything down to 2D, which the stereoscopic snobs would call 2.5D. It’s amusing to see this idea turned around on them.

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