Tridelity has manufactured an autostereoscopic display, which means that you don't need glasses for the
stereoscopic experience. Get to know the basic functionality and how your content has to be preprocessed.
This is achieved by among other things the application of optical technologies and elements (so called parallax barrier or lenticular lens panes)
that ensure that each eye of the viewer sees a slightly different perspective. The human brain then processes these perspectives to a spatial picture.
Visit the Tridelity Technology Page to read the rest of this quote.
The display needs 5 streams of your movie. In comparison with 2 streams for anaglyph and polarized filter solutions this seems quite a lot,
but the experience is very nice. Of course your render time and data storage explodes, when you are rendering out of 5 cameras.
But if you have in mind that other systems need even 9 streams you will feel relieved. Other displays use a quite different method and
generate autostereo with a depth channel, for example. I haven't worked with such systems, so it won't be a subject here. I just want
to show you that every autostereoscopic display needs a individual treatment and an appropriate preparation of data.
How the tridelity display works schematically:
The Tridelity display overlays the five streams in a special way, to get a stereoscopic experience.
So your eyes will get the information of all 5 streams at the same time. Divided into your left and right eye, of course.
When you are standing in front of the screen there are certain positions where you have a good stereoscopic effect.
This is when your eyes are getting all 5 streams. As soon as you walk around you will see the movie jumping.
Thats because you are at the critical point (marked in the graphic), where two sets of streams are next to each other.
At this point your left eye looks at the right streams of set 3 and your right eye gets the first streams of set 4.
That's where the illusion breaks. But what I want to show here is how the display works. When you've found the
right position, your eyes see stream 2, 3 and 4 simultaneously. When you move your head slightly you will get
stream 1 or 5 additionally.
How to create content for Tridelity displays:
First you have to setup your five stream camera rig. Basically you can take the distance you would choose for adual camera setup and add the three cameras in between. One in the center and two in the middle of the three
cameras. This works really good for the basic setup, but you can still try to optimize the stereoscopic impression.
This is also helpful, if you want to generate an anaglyph video out of your five streams. Just take the two outermost cameras.
How to compile the video file for a full screen solution:
You have to stack the 5 streams in a certain way, so your movie gets interpreted correctly by the Tridelity player.
First you have to create a composition with the following proportions: 1920 x 1350 px
Every stream needs to have the following size: 960 x 540 px
The cameras in your 3D application have the following order:
(left) Cam1 | Cam 2 | Cam 3 (center) | Cam 4 | Cam 5 (right)
Now here is the order you want in your composition:
Notice that the last image is divided into two parts.
This way the whole available space is filled and there are no useless black areas.
Now here is the most important need to know about the Tridelity player:
You have to use a Xvid compression to make your video work correctly.
I didn't know that at the beginning and had real headaches why the player
always messed up my movies. As soon as I had the Xvid compression
everything worked fine. For testing purposes you can also render out
stills in .tiff format. We made several disparity tests this way.
Related Links:
Tridelity - the website of the company
Spatial View - a stereo Plug-In for several programs
"Autostereoscopic display by Tridelity" by Stefan D. Voigt is licensed under a
Creative Commons Attribution-NonCommercial 3.0 Germany License.
Permissions beyond the scope of this license may be available here.
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