3D Rotatable Formats

Many of the samples on my website have 3D real-time rotatable images. They are made by photographing the sample from 72 different angles around a complete circle, using a turntable. There are three different ways you can choose to view these rotatable images, each with its own advantages and disadvantages.

QuickTime VR
QuickTime VR is a technology developed by Apple that allows you to navigate around a virtual 3D object, rotating it and zooming in or out. It works as a browser plugin, so you need to have the plugin installed. If you're using a Macintosh of course you already have it, and if you're using Windows you can download the latest version free from Apple's QuickTime Download Site. My QuickTime VR files are about 3-5MB each, so they may take a while to load.

Side-by-side Stereo Pairs
QuickTime VR provides a nice interface for rotating an object, but it's not as realistic as seeing an image in true 3D, which is possible only by showing each eye an image from a slightly different angle. The Side-by-Side viewing option presents the same 72 images two at a time, offset by one frame. By showing two neighboring frames next to each other, you can see true stereo 3D, provided you can get one image to go to one eye and the other to the other eye. Some people can do this just by staring really hard and allowing their eyes to diverge (easier with smaller size images), or you can use a pair of stereopticon viewing glasses. Move the mouse over the pair of images to rotate the object in real time.
The total amount of data needed to view the object from all sides is about the same as for the QuickTime VR, 3-5MB. Rotation will be very jerky until your browser has loaded all the images, which may take a while.

Interleaved Stereo
These images can only be properly viewed using a pair of LCD shutter glasses, available for $70 from edimensional.com. In this mode each frame consists of two neighboring views interleaved on odd/even lines of the screen. The glasses and monitor adapter (compatible with nearly any external CRT monitor) have the effect of showing odd lines to one eye and even lines to the other eye. This has the advantage of not requiring you to look crosseyed, at the expense of needing the very special glasses.

You can switch between viewing options by clicking the appropriate labeled area at the top of the sample page. Close this window to go back and choose a stereo mode.

Amusingly, I was able to generate these interleaved images using an incredibly short Mathematica program. Here is the complete text of the program to process a directory full of views into a set of interleaved images:

InterleaveImagePair[{file1_, file2_}, fileOut_] := Module[{g1, g2, imagePair},
    g1 = Import[file1];
    g2 = Import[file2];
    imagePair = {g1[[1,1]], g2[[1,1]]};
    Export[fileOut,
        ReplacePart[g1, Table[imagePair[[Mod[i, 2, 1],i]], {i, Length[imagePair[[1]]]}], {1, 1}]];
]

InterleaveFrameList[indir_, outdir_] :=
    Map[InterleaveImagePair[#, StringReplace[#[[1]], indir -> outdir]] &,
        Partition[FileNames["*.JPG", {indir}], 2, 1, {1, 1}]]

I think that's a pretty amazing bit of programming efficiency!

Text and all images on this page Copyright (c) 2003 by Theodore W. Gray.