Large viewing angle floating three-dimensional light field display based on the spatial data reconstruction (SDR) algorithm

The theory of cartographic projections is a tool which can present the convex surface of the Earth on the plane. Of the many types of maps, thematic maps perform an important function due to the wide possibilities of adapting their content to current needs. The limitation of classic maps is their two-dimensional nature. In the era of rapidly growing methods of mass acquisition of spatial data, the use of flat images is often not enough to reveal the level of complexity of certain objects. In this case, it is necessary to use visualization in three-dimensional space. The motivation to conduct the study was the use of cartographic projections methods, spatial transformations, and the possibilities offered by thematic maps to create thematic three-dimensional map imaging (T3DMI). The authors presented a practical verification of the adopted methodology to create a T3DMI visualization of the marina of the National Sailing Centre of the Gdańsk University of Physical Education and Sport (Poland). The profiled characteristics of the object were used to emphasize the key elements of its function. The results confirmed the increase in the interpretative capabilities of the T3DMI method, relative to classic two-dimensional maps. Additionally, the study suggested future research directions of the presented solution.

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Full-chain modeling and performance analysis of integral imaging three-dimensional display system

Journal of the European Optical Society Rapid Publications ◽

10.1186/s41476-020-00134-7 ◽

2020 ◽

Vol 16 (1) ◽

Cited By ~ 1

Author(s):

Ying Yuan ◽

Xiaorui Wang ◽

Yang Yang ◽

Hang Yuan ◽

Chao Zhang ◽

...

Keyword(s):

Optimization Design ◽

Quality Evaluation ◽

Light Field ◽

Three Dimensional ◽

Display System ◽

3D Display ◽

Performance Characterization ◽

Integral Imaging ◽

Characterization Model ◽

Display Quality

Abstract The full-chain system performance characterization is very important for the optimization design of an integral imaging three-dimensional (3D) display system. In this paper, the acquisition and display processes of 3D scene will be treated as a complete light field information transmission process. The full-chain performance characterization model of an integral imaging 3D display system is established, which uses the 3D voxel, the image depth, and the field of view of the reconstructed images as the 3D display quality evaluation indicators. Unlike most of the previous research results using the ideal integral imaging model, the proposed full-chain performance characterization model considering the diffraction effect and optical aberration of the microlens array, the sampling effect of the detector, 3D image data scaling, and the human visual system, can accurately describe the actual 3D light field transmission and convergence characteristics. The relationships between key parameters of an integral imaging 3D display system and the 3D display quality evaluation indicators are analyzed and discussed by the simulation experiment. The results will be helpful for the optimization design of a high-quality integral imaging 3D display system.

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Turbulent three-dimensional dielectric electrohydrodynamic convection between two plates

Journal of Fluid Mechanics ◽

10.1017/jfm.2012.30 ◽

2012 ◽

Vol 696 ◽

pp. 228-262 ◽

Cited By ~ 24

Author(s):

A. Kourmatzis ◽

J. S. Shrimpton

Keyword(s):

Spatial Data ◽

Three Dimensional ◽

Reynolds Numbers ◽

Two Dimensions ◽

Three Dimensions ◽

Energy Budgets ◽

Turbulent Regime ◽

Scalar Flux ◽

Wide Range ◽

Scalar Variance

AbstractThe fundamental mechanisms responsible for the creation of electrohydrodynamically driven roll structures in free electroconvection between two plates are analysed with reference to traditional Rayleigh–Bénard convection (RBC). Previously available knowledge limited to two dimensions is extended to three-dimensions, and a wide range of electric Reynolds numbers is analysed, extending into a fully inherently three-dimensional turbulent regime. Results reveal that structures appearing in three-dimensional electrohydrodynamics (EHD) are similar to those observed for RBC, and while two-dimensional EHD results bear some similarities with the three-dimensional results there are distinct differences. Analysis of two-point correlations and integral length scales show that full three-dimensional electroconvection is more chaotic than in two dimensions and this is also noted by qualitatively observing the roll structures that arise for both low (${\mathit{Re}}_{E} = 1$) and high electric Reynolds numbers (up to ${\mathit{Re}}_{E} = 120$). Furthermore, calculations of mean profiles and second-order moments along with energy budgets and spectra have examined the validity of neglecting the fluctuating electric field ${ E}_{i}^{\ensuremath{\prime} } $ in the Reynolds-averaged EHD equations and provide insight into the generation and transport mechanisms of turbulent EHD. Spectral and spatial data clearly indicate how fluctuating energy is transferred from electrical to hydrodynamic forms, on moving through the domain away from the charging electrode. It is shown that ${ E}_{i}^{\ensuremath{\prime} } $ is not negligible close to the walls and terms acting as sources and sinks in the turbulent kinetic energy, turbulent scalar flux and turbulent scalar variance equations are examined. Profiles of hydrodynamic terms in the budgets resemble those in the literature for RBC; however there are terms specific to EHD that are significant, indicating that the transfer of energy in EHD is also attributed to further electrodynamic terms and a strong coupling exists between the charge flux and variance, due to the ionic drift term.

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Metalens Eyepiece for 3D Holographic Near-Eye Display

Nanomaterials ◽

10.3390/nano11081920 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1920

Author(s):

Chang Wang ◽

Zeqing Yu ◽

Qiangbo Zhang ◽

Yan Sun ◽

Chenning Tao ◽

...

Keyword(s):

Light Field ◽

Three Dimensional ◽

Fresnel Diffraction ◽

Virtual Image ◽

Display Devices ◽

Computer Generated Holography ◽

Wavefront Shaping ◽

3D Scene ◽

Optimum Solution ◽

532 Nm

Near-eye display (NED) systems for virtual reality (VR) and augmented reality (AR) have been rapidly developing; however, the widespread use of VR/AR devices is hindered by the bulky refractive and diffractive elements in the complicated optical system as well as the visual discomfort caused by excessive binocular parallax and accommodation-convergence conflict. To address these problems, an NED system combining a 5 mm diameter metalens eyepiece and a three-dimensional (3D), computer-generated holography (CGH) based on Fresnel diffraction is proposed in this paper. Metalenses have been extensively studied for their extraordinary capabilities at wavefront shaping at a subwavelength scale, their ultrathin compactness, and their significant advantages over conventional lenses. Thus, the introduction of the metalens eyepiece is likely to reduce the issue of bulkiness in NED systems. Furthermore, CGH has typically been regarded as the optimum solution for 3D displays to overcome limitations of binocular systems, since it can restore the whole light field of the target 3D scene. Experiments are carried out for this design, where a 5 mm diameter metalens eyepiece composed of silicon nitride anisotropic nanofins is fabricated with diffraction efficiency and field of view for a 532 nm incidence of 15.7% and 31°, respectively. Furthermore, a novel partitioned Fresnel diffraction and resample method is applied to simulate the wave propagations needed to produce the hologram, with the metalens capable of transforming the reconstructed 3D image into a virtual image for the NED. Our work combining metalens and CGH may pave the way for portable optical display devices in the future.

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