Floating Windows_ please help me understand

[Philip Powell]

I have read about Floating windows, but not certain I get them. Please confirm, correct and elaborate.

The purpose of Floating Windows - Putting it in my own words - They serve three basic functions:

1. To snug up the left and right images, so that no objects are visible on only the left or right eye. This is usually equal in pixels to the amount of IO between the images.

2. To deal with negative parallax stereo window violations. I.E when an object enters or exits frame while in negative parallax. This is achieved by literally cropping the left and or right image in towards the center, i.e making the projected image actually smaller.

The reason this is done is to prevent depth cue conflicts when an object in negative Z space exits fame AT the apparent screen plane edge. When you crop the image in, and visually disassociate it from the actual screen plane edge, objects in negative Z space can enter and or exit cleanly on this new exit line, that is no longer at the screen plane edge. It APPEARS to the audience that this new exit line is a "floating negative Z window" (albeit smaller and still hard edged) that is contained WITHIN the boundaries of the actual screen plane edge.

If successful, audiences are not bothered by objects entering or leaving frame because you have "eliminated" the depth cue conflict caused by the actual screen plane.

3. It is used for effects, i.e to potentially convey a greater sense of depth, by cropping in one edge more than another and creating more apparent negative "pop" on other side.

Thanks for enlightening me.

 

[Fabricio Morato]

Hi,

The stereoscopic floating window is an artistic process were you create a virtual window in negative parallax. This is great when you have an object/character that violates the frame (and you don't want to leave it like this or do a depth grade to put everything behind the screen plane). You then create this stereo floating windows and "put it" in front of this object. So if the object is 0.5% in negative parallax, you put this window in 0.6% negative. So this virtual window appears to be in front of this object/character and you get the illusion that theres a "real window" in front of the object and that this object is not violating the screen plane.

Hope this helps...

 

[Tim Hole]

Have a listen to RC #81 it is discussed there.

Here is something you might find additionally interesting from a projection prospecive.

[video]http://www.cinetechgeek.com/2009/08/11/3d-windows-and-masking-for-3d-in-cinemas/[/video]

 

[Jason Goodman]

Floating windows have been largely abandoned. In theaters, overprojection almost always ruins the effect. In the home, higher levels of ambient lighting, and the television's frame itself ruin the effect. It may be best to find other ways to protect against edge violations.

 

[Stephen Strangways]

Floating windows have been largely abandoned.

Most of Disney's 3D movies make extensive use of floating windows.

 

[Philip Powell]

So this virtual window appears to be in front of this object/character and you get the illusion that theres a "real window" in front of the object and that this object is not violating the screen plane.

How would I put a floating window "in front" of an object? I thought the key concept here was to disassociate it from the screen plane by cropping it in, or am I missing something? @ everyone, Again, thanks for you comments and corrections. I may try to post some examples of my thinking. @ Jason, interesting to hear they aren't used as much because if I understand you correctly, theatres are screwing the effect because they are scaling up their projections, thus reconnecting the stereo voiloations with the actual screen plane and ruining the effect? More or less correct?

 

[Fabricio Morato]

Sorry I've only got access to MS Paint right now =P

So you basically offset your stereo window to a little more than the object that is violating.. this way it appears to be in front of it.

Hope this helps

 

[Jason Goodman]

@Stephen, I said largely abandoned, not completely. They were first used on Meet the Robinsons. Phil McNalley and Brian Gardener were the driving forces behind this. We would have to check if Megamind (Phil's most recent work) used them, it probably did, but I am not sure if they will continue moving forward. As I said, and as Philip noted, over projection in the theaters casues the effect to be lost. It is a time consuming (and therefore costly) element to add so I think most productions would want to avoid it.

 

[Philip Powell]

Sorry I've only got access to MS Paint right now =P

So you basically offset your stereo window to a little more than the object that is violating.. this way it appears to be in front of it.

Hope this helps

View attachment 13914

Thanks for the example, it looks like my understanding is more or less correct I suppose, but please feel free to jump in and correct. @Jason, thanks for the information, very helpful. If folks are no longer (for the most part) using FW, what method are they using to handle these types of situations? Are they pushing things into pp more, or just living with neg stereo "violations"?

 

[Markus Lanxinger]

I've not seen a lot of floating windows in current productions other than animation. However if used effectively it can really enhance the 3D experience. You can create floating windows in any image editor. Its basically cropping part of the image so it will seem that there is a semi-transparent bar floating in front of the other eye which pushes everything back into positive space.