Martin Fuchs1,
Ramesh Raskar2,
Hans-Peter Seidel1, and
Hendrik P. A. Lensch1
1 MPI Informatik
2 Mitsubishi Electric Research
Laboratories, now at MIT media lab
Traditional flat screen displays (bottom left) present 2D images. 3D and 4D displays have been proposed making use of lenslet arrays to shape a fixed outgoing light field for horizontal or bidirectional parallax (top left). In this article, we present different designs of multi-dimensional displays which passively react to the light of the environment behind. The prototypes physically implement a reflectance field and generate different light fields depending on the incident illumination, for example light falling through a window.
We discretize the incident light field using an optical system, and modulate it with a 2D pattern, creating a flat display which is view and illumination-dependent. It is free from electronic components. For distant light and a fixed observer position, we demonstrate a passive optical configuration which directly renders a 4D reflectance field in the real-world illumination behind it.
A demonstration for this is shown on the right: outside illumination falls through an office window on a display prototype in front. As the sunlight moves with the changing time of day, the shadows, highlights and caustics naturally follow the movement.
We further propose an optical setup that allows for projecting out different angular distributions depending on the incident light direction.
Combining multiple of these devices we build a display that renders a 6D experience, where the incident 2D illumination influences the outgoing light field, both in the spatial and in the angular domain. Possible applications of this 6D display technology are time-dependent displays driven by sunlight, object virtualization and programmable light benders / ray blockers without moving parts.
Our display designs transform the incident light field and modulate it so that a rendering occurs which varies in each pixel with the incident direction. Consider the video on the right: as the light incident from the left passes through the lens array, it is focused on a modulator plane. There, a pattern attenuates the light according to its location and direction. Then, the light is projected onto a diffuser screen, where each of the individual contributions adds up.
Please refer to the full article or the video below for more details and alternative designs.
Towards Passive 6D Reflectance Field Displays [.pdf, 2.1 MB]
Martin Fuchs, Ramesh Raskar, Hans-Peter Seidel, and Hendrik P. A. Lensch
Towards Passive 6D Reflectance Field Displays [.mov, 62 MB, 640 x 480 @ 30 fps]
Martin Fuchs, Ramesh Raskar, Hans-Peter Seidel, and Hendrik P. A. Lensch
Unfortunately, we only learned after the finalization of the article about previous experiments recording light-variation of a real-world scenes in a hologram. The references are:
Please note that the embedded videos require a Macromedia Shockwave Flash plugin and may not display properly if it is not available.