the bblog

coraline and the future of 3D movies

I finally saw Coraline the other day, but since it was blogged to death when it came out about a billion years ago I won't natter too much about it, other than it was pretty good, and I rather liked it, though I could have done with some nerdy worldbuilding details that were pretty much handwaved.

Like, what's the deal with the Beldam? Why is she kidnapping children? What's with the buttons? Is the other world some kind of pocket universe, or what? You can tell me, movie, it's okay! I would like to know.

No, what I'd like to talk about is one of the trailers, specifically, the one for Battle For Terra. Nitpicks? You bet your ass I've got some nitpicks!

First off, the trailer (which was in 3D) highlighted some of the problems with the technology.

The 3D illusion is a good but still decidedly imperfect illusion. The way this particular 3D scheme works is to project images for each eye alternately, polarized in opposite directions. The 3D glasses contain polarization filters, which only let the intended image through to each eye. This works... fairly well, but has some significant limitations, the primary one being that the glasses are not perfect, being a compromise between reducing light attenuation, and preventing image crosstalk. The more the filters cut out unpolarized light, the darker the screen appears, and the more washed out the colors are. So these glasses are a compromise between preserving color vibrancy and image brightness, and preventing each eye from seeing the image meant for the other. It does neither well, with muted colors, and noticeable double image ghosting.

Image crosstalk isn't a terribly big problem except at deep image depths, when the eye images are moved apart to simulate 3D depth. When this happens you end up with three images, the composite image of both eyes, and two ghost images. This is visible at any image depth, but glaringly obvious at deep depths.

In addition, the persistence of vision effect is greatly reduced when the projector alternates between each eye image, which only manifests with fast movement of on-screen elements. Rather than a smooth blur, you see a series of still images.

So, the three major limitations here are bright colors, deep depth effects, and fast movement. These are serious, but by no means showstopping, as aptly demonstrated by Coraline. But you really have to keep them in mind during scene composisition and editing, and display restraint when it comes to fast movement, bright colors, and deep depth. Critics lauded Coraline's stately pacing, atmospheric staging, and general maturity. These are actually technical limitations, which Coraline's producers cannily exploited, but will be a problem for other 3D films, in two ways.

For one, "restrained maturity" is inimical to the movie trailer, an advertisement consisting entirely of fast cuts between an upcoming movie's most spectacular scenes, and, being an advertisement, is supposed to be as flashy and over the top as possible. So a compromise is struck, an inevitably poor compromise, which is a shame, since any 3D movie is going to start with a string of examples of How Not To Do It.

For two, doing 3D is much, much easier for a CGI movie, since all you have to do is create a second camera object.[*] In the meatspace, a 3D camera will be, at the very least, twice as heavy as a 2D camera, and quite likely more. It'll also be quite a lot more than twice as expensive, use twice as much "film", require specialized operators, editors; essentially an entire different toolchain. A significant risk, for an entirely untried format.

*: Harder to do well, I suspect, but I shall reserve my judgement until one of these movies actually comes out.

So, for maybe the next year or five, 3D will mean CGI, and unfortunately for the format, CGI means Kids, and movies targeted to children are also not known for "restrained maturity". Coraline is supposedly a kids movie, which is pretty much an out-and-out lie. Pixar might be able to pull it off with Up, but Battle For Terra? Well, let's get a plot summary.

A species of peaceful aliens who have advanced beyond our materialist culture are threatened with extinction by what remains of the human race after the destruction of Earth.

Hey, how much do you want to bet they figure out how to coexist peacefully after two members of their respective species find love?

Actually, the trailer makes a manful attempt to portray the invasion as a mortal dilemma; though the chances of the movie actually exploring this problem beyond "people who invade other countries planets are bad" are zero.

This cliche storm isn't perfect without obligatory space fighters and an utterly moronic narrative choice to name the alien planet "Terra".

In other words, Battle For Terra looks like a piece of garbage, and I can't wait for it to come out so I can tear it a new one.