Ultra-realistic virtual object representation is an old dream of humanity. From the 3D Paleolithic rock painting to the late Michael Jackson holographic shows, humans have investigated display solutions to give life to the abstraction. The incredible opportunities given by the digital revolution have paved the way to the recent development of innovative volumetric displays. These complex solutions are however still limited in the visual experience they can offer to the viewer. In a more concerning manner such devices often appear as empty shells as their effective usefulness is not yet clearly defined. Recently, we have proposed an original volumetric display concept based on a 360° projection configuration. Inspired from the pepper ghost concept and from the praxinoscope design of the end of the XIX century, our display mixes real projection on transparent retroreflective surface and virtual images superimposition. This development has been made in collaboration with a group of live performing artists in France. The 360° display has been used to present an original creation of the artists and the confrontation with the public has highlighted some unexpected properties of this family of displays. We describe here the technological concept of our display and the evolutions we target to improve the visual rendering. The collaboration project with the artists is also presented and we give our analysis on the feedback of the public.
From the first ultra-realistic 3D images in the sixties to the most recent Augmented Reality devices, the field of holography has been involved in display technology for a long time. The spectral selectivity of the hologram reflection together with the very good transparency of the holographic material make it a suitable option for some of the key optical components in smart glasses. However, these devices are still very limited by the overall optical system based on the conventional scheme Display - Optical System - Combiner. Recently, we have proposed an unconventional scheme that puts the hologram at the core of the display device. Due to its 3D nanoscale complexity, the dynamic updatable hologram display is still an unreachable goal. As an alternative, our configuration is based on a concept of switchable static holographic elements. These elements are interleaved on the surface of the display and form various groups of emissive point distributions that are phase-adjusted for given angular directions. The activation of these holographic elements produces angular planar wavefronts in the far field and the display is expected to achieve retinal projection without the help of an optical system. We present our concept and describe the development of the optical set-up used to investigate our holographic configuration. We record phase-adjusted distributions of holographic elements that are multiplexed on the surface of our sample, each distribution targeting a specific angular direction. First recording results on a holographic photopolymer are given.