Floating windows?

[dcoplan]

Can someone dumb this down for me? As far as I understand it, floating windows are used at the edges of the frame to compensate for edge violations. But I'm confused as to how they actually work and how to implement them when working on my own stuff.

[technica3d_admin]

Humans are wired to view dangers from all around. But through our peripherals humans evolved peripheral site which allows us to notice changes in our field of view even though its only through one eye. There is a difference in say the right eye that the left eye doesn't see but the brain notices it as a defense mechanism.

Now take that same concept and move it to the stereoscopic shooting world. When shooting to get a stereo pair, we are getting obviously the right and left eye. Well when an object is near the edge - edge violation, see where I am going with this - one eye may see more than another eye. If say you have a palm tree barely on the left side edge of your frame, the left eye may not see the tree but the right eye may. Now your brain is interpreting that as something to take notice of it because its occurring in our peripheral. So now this edge violation creates an effect that the brain interprets as a danger or just plain bad. Now if its an item that is moving quickly off of the screen then the brain just interprets that as a fast moving object because there isn't enough time to convert that object into separate images. But being something very slow or even stationary (our palm tree) violating the edge will cause the brain to react negatively.

The moral is watch your framing and beware of edge violations unless they are quick.

[dcoplan]

I understand that, but how do floating windows work and how are they implented?

[Pedro Guimaraes]

You asked so here is a rather extensive explanation.

As explained by Stereoscopic expert Brian Gardner (Meet the Robinsons, Coraline). He also lays claim to inventing "dynamic floating windows"

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"One of the keys to using depth as a creative tool is to understand how it works in relation to the frame. When you watch a 2D movie, you're aware that the screen is on a wall. In 3D, the screen acts more like a hole in the wall, a window into the world of the story, with action taking place in a physical space on either side of it.

If there is an actor who is only partially onscreen in 2D, you understand that the rest of the actor is "behind" the frame. But if you were to take that exact same shot in 3D, and the character was on the audience side of the screen, you'd see half the character floating in the air!

Part of your perceptual system says, "I can only see half of the person, because the other half of him is behind the window, so he's behind the window." Then your stereo system says, "The window frame is behind him, but half of him is way in FRONT of the window! That's not possible!"

We call that a "window violation," when something you see breaks your perceptual system. This conflict causes eyestrain and headaches. If there's a lot of motion, it can even induce vomiting. People are not used to having their perceptual systems in that much conflict for long.

In 1953, Raymond and Nigel Spottiswoode created a short called "The Black Swan." They believed that the "movie" world should never come into the "audience" world. It was an issue of separatism. They rationalized that they could relocate this window into a fixed position, away from the theater wall, by adding a static black mask to their film, which was made slightly different for the left and right views.

In fact, they floated it halfway out into the theater to prevent any 3D object from accidentally coming into the "audience" world. There would never be a window violation, because everything would always be behind the window.

Audiences didn't like it at all. They could clearly see this static window floating in front of them, and it was distracting. Also annoying was that it created retinally rivalrous areas, large areas at the sides of the frame which could only be seen in one eye. It created more problems than it solved, and was never used again in 3D movies.

Now, when I was in college, I studied the stereograms of Béla Julesz, a perceptual psychologist. He used what looked like random dots to create stereo images on paper.

One of my homework assignments was to replicate Béla Julesz's random dot stereogram experiments.

And I messed it up!

But it was kind of an interesting mistake, so I started to explore it - which is the difference between a technologist and an artist. Technologists find bugs, and fix them. Artists find bugs, and explore them.

I started grappling with, "Why is the frame of the stereo image floating up off the page? Why don't I perceive the paper as falling backward, away?" Instead of random dot stereograms, I started applying it to animation and realized, "Hey, I've got this floating stereo window, and I can move it all over the place!"


I realized that I could lift it off the screen, or push it behind the screen. I could tilt the top toward or away from the audience, kind of a Dutch Tilt but in 3D space. I could rotate it, and even animate it - anything at all. By digitally manipulating the image borders, the window can be highly dynamic.

With the frame moving around so much, you'd think that it would be easy to detect. But when combined with the animation on the screen, you can't see it at all.

It turned out that the failure of the Spottiswoode brothers was that their floating window was static, which made it obtrusive. The new Dynamic Floating Windows, which were moving all over the place, were not even visible at all.

Their invisibility came because they are dynamic.

It was hard for me to convince other industry people that Dynamic Floating Windows would work, because the idea seemed so counter-intuitive to them. They thought that the window changing so much would be too distracting to the audience.

This is like the evolution of editing. It took a little while to figure how to make cuts invisible. Now, it's weird that a cut that changes camera position, maybe the position in time, sometimes even both - the audience doesn't notice it. People are fine with it. Yet, a Jump Cut, when the camera positions are more similar, is jarring. At first, invisible cuts seemed illogical.

The discovery of Dynamic Floating Windows suddenly opened this whole range of possibilities for 3D storytelling. It gave us the ability to get rid of all the window violations, and gave us a tool for dynamically controlling how we use depth in a scene.

The first time I used dynamic floating windows for storytelling was on "Meet The Robinsons," and it was a revolution that quickly spread. Almost every 3D commercial animated film since then has used them - "Beowulf," "Bolt," "Monsters vs. Aliens," Pixar's "Up," and even "Fly Me to The Moon" from nWave Pictures, a relatively small production company.

"Meet The Robinsons" wasn't just the first time that I got to use Dynamic Floating Windows in a movie. It was also the first time that I really started thinking of them as not just a fix for a technical 3D problem, but as a way to use the 3D window as an artistic tool and a cinematic element.

I used them with stop-motion in "Coraline," and I intend to use them for a live-action movie that I'm working on, still in the planning stages. This may very well be the first time that Dynamic Floating Windows will be used for live action.

I certainly hope so! Though, somebody may get there first, but it would be unfortunate if someone beat me to using my own tool for live action 3D!

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