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Stereo_3D_Guide
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ANTz - data visualization for the mind.
Stereo 3D Guide
There is a branched version of ANTz that supports the [zSpace] by Infinite Z. A desktop VR solution that includes stereoscopic 3D with head tracking and 3D stylus.
At the moment you will need to contact us in order to get the IZ version. This will change in the near future and we will provide the IZ version as a public download.
An planned update to ANTz will allow for Stereoscopic 3D on any system with suitable hardware. In general ANTz is an OpenGL based program which means only nVidia Quadro series cards and AMD ATI Fire series cards will work for Stereo 3D.
At this time, OpenGL Stereo 3D is only supported by the professional series cards from nVidia (Quadro series) and ATI (Fire series). This is a very unfortunate marketing decision by the hardware manufactures and has nothing to do with ANTz.
Stereoscopic 3D Content Best Practices
... this is a rough draft, more to come!
Stereo 3D content creation is Art and not Science!
This document is a brief overview of Stereo 3D issues specifically tailored to small format (24" screens.) Medium format (42-70") and large cinema screens work quite differently. A primary difference between traditional Stereo 3D and VR is that of head-tracking which corrects the 3D perspective based on viewer position in relation to the screen. VR has additional constraints as a result of providing true perspective.
Content needs to be specifically formatted for a VR Stereoscopic 3D environment. For the most part, the same rules apply to VR as that of non-VR Stereo 3D. But, you are not able to play all the same tricks as used by traditional stereoscopic approaches. For example, there is currently no known VR equivalent to the traditional 3D concept known as 'convergence', (as used in the entertainment industry.)
Avoid breaking frame! This is perhaps one of the most important guidelines, (remember it's art not science and there are no rules.) Breaking frame is where an object that has an apparent position above the screen surface is clipped by the sides of the screen. Think in terms of looking through a window, an object behind the window that is partially obscured is normal. Versus an object in front of the window that is clipped by the window edge is very difficult for the brain to interpret as this does not ever happen in the real world. This will cause the viewer to immediately reject the illusion of 3D depth perception and will instead see images as flat for a period of several minutes following the event. Usually the user is much more permissive with objects that break frame on the top and bottom of the screen, though this is still undesirable. Conversely, it is usually not a problem when an object that appears behind the screen is clipped by the frame. Certain displays systems such as VR Cave environments remove this problem all together by providing full peripheral vision.
Scale and place objects near the focal plane, (screen surface.)
The comfortable depth range for an object is based on the distance of the viewer from the screen. With large theater screens, the comfort range is from infinity to about 4 feet in front of the viewer. With small screens the comfort range is roughly about 0.5 to 1.4 meters. A medium format (TV) screen at 3 meters from the viewer allows for objects from 1 meter away to infinity. This poses a fundamental problem where if you want objects within arms distance then you must have a screen that is quite close, but this disallows objects at infinity. See the chart below for a graph on 'Zone of Comfort'.
For example, with the [zSpace], it is very important not to allow for objects or the ground plane to extend to infinity, (far into the background.) With a small 24" display, the comfortable viewing range of objects is near the screen plane. Idealy apparent position should be no more then a few inches in front of or in back of the screen (focal plane.)
ANTz uses a custom algorithm that effectively scales the entire scene to place the currently selected object at the screen focal plane. Keep in mind that this position is based on the Root Pin and does not take into account the structure of child branches.
Apparent ghosting can be reduced by composing the scene and background within a relatively narrow range of contrast, hue and brightness.
The Oobe demo (by IZ,) keeps things close to the focal plane by looking down on scene and reduces apparent ghosting by using a narrow contrast range.
Transparency, texture and movement all help with 3D depth perception!!!
The experience and comfort level of individual viewers varies wildly. Testing with several users that have different amounts of prior exposure to Stereo 3D is important. It is crucial to test using the actual display.
When creating stereoscopic content, Screen Size Matters!
