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Capturing the Images
There are two basic methods that can be used to render out
the proper images to turn your 3D computer graphics into a
3D hologram. The first is to use a stationary virtual camera,
and rotate your subject 180 degrees, capturing one image every
1 degree. For simple computer graphics scenes this is an easy
technique to use. The second method is to create a virtual
camera that travels along a circular path around your subject,
again capturing one image every 1 degree as the camera travels
180 degrees. For more complex scenes this is the best approach,
as it may be more difficult to rotate all the objects in your
model than to create a circular camera path.
It is important to note that the center of rotation of the
camera (whether you rotate the model, or rotate the camera)
will determine what part of your model projects out in front
of the holographic film, and what part of your model appears
to be behind, or "inside," the hologram. Objects
between the camera and the center of rotation will appear
to "project" out in front of the hologram, while
objects located beyond the center of rotation will appear
to be "inside" the hologram. And of course, objects
at the center of rotation will appear to be located on the
surface of the hologram film.
It is also important to be aware that holograms exhibit a
type of "holographic depth of focus," similar to
depth of focus in photography. This means that objects located
closest to the surface of the hologram film (closest to the
center of rotation) will be the sharpest and clearest. Objects
that are farther from the hologram film, whether projected
in front or positioned inside the hologram, will gradually
lose sharpness as they get farther from the surface of the
hologram film. So important objects, detailed objects, and
any text should be located as close to the surface of the
hologram film (and thus the center of rotation) as possible.
As a very general rule of thumb, we recommend limiting the
projection of objects in front of the hologram to about 30%
of the total width of the hologram, and limiting the position
of objects inside the hologram to less than about 50% of the
width. This would mean that for a 12 inch wide hologram, it
would be helpful to limit object projection to less than 4
inches, and keep important objects within about 6 inches deep
inside the hologram. But remember, this is your hologram,
so feel free to break these rules at any time and experiment.
Image Resolution
We recommend rendering the images out at a resolution of 1024x768
pixels. The Liti3D hologram technique loses a bit of this
resolution in the processing, but it is always better to start
out with higher quality images, if possible. We have on occasion
made holograms with resolutions as low as 320x240, and still
had reasonably good results.
File Formats
If possible, we prefer to receive the individual rendered
images in BMP format. However, TIFF also works well, or sending
the images in Quicktime or AVI movie formats. If necessary,
we can often use many other image and movie formats.
Sending Your Images to Liti
After you place your order for your custom Liti3D hologram,
you will be given a special e-mail address to which you can
send your images or movie. If the total size is larger than
about 50MB, we request that you use a .zip format to compress
the images or movie file first.
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