Glasses-Free 3D On iPad (Sorta) 96
johkir writes "The Engineering Human-Computer Interaction (EHCI) research group has created an apparent 3D effect on the iPad 2. Called the Head-Coupled Perspective, it uses the front camera to track the relative changes in the position of the user's head."
Hey! (Score:3, Informative)
Re:Smart... (Score:5, Informative)
1. Focal depth: based on how much the eye's lens has to focus
2. Convergence: based on the slight differences in pointing of the two eyes to a target
3. Stereopsis (static parallax): based on the slight differences between the left and right eye images
4. Motion parallax: based on the different displacements/motions of objects at different distances (e.g. as you move your head)
5. Visual inference: reconstructing using cues like occlusion, lighting, etc.
In the real world, all 5 of those systems work in concert, giving you a consistent understanding of your environment. The problem with modern 3D implementations is that they only trick you using only two, or maybe three, of the above. For instance "3D glasses" are showing you different left/right images, creating fake stereopsis, but the focal distance is still "to the screen" and doesn't match the apparent parallax-based distance to objects. So your brain is rightly confused because the various systems are giving conflicting answers. Amazingly our brains have no problem looking at two-dimensional images like pictures and conventional movies: in such cases 1-4 don't work, and our brains instead just use #5 to fully reconstruct/guess at the three-dimensional nature of the scene. A few optical illusions notwithstanding, this works remarkably well.
What's presented in the above video is fooling your brain using motion parallax. This is neat, but because the image is still flat, your other brain systems (1-3) will be giving a different answer and so the illusion won't be perfect.
In principle we could combine techniques to make for a more convincing sort of 3D. E.g. combine motion parallax (eye tracking) with stereopsis (3D glasses). But it won't be truly convincing (and thus headache-free) until we fully reconstruct the three-dimensional light-field that should properly be emanating from the virtual objects. Doing this requires some very good holography, to fully reconstruct the required light waveforms, or something like anisotropic pixels that can control their emission as a function of viewing angle. In the meantime, 3D will remain a bit of a gimmick outside of some niche applications.
Re:Smart... (Score:4, Informative)