Continuous shading and its fast update in fully analytic triangular-mesh-based computer generated hologram

Abstract

Fully analytic mesh-based computer generated hologram enables efficient and precise representation of three-dimensional scene. Conventional method assigns uniform amplitude inside individual mesh, resulting in reconstruction of the three-dimensional scene of flat shading. In this paper, we report an extension of the conventional method to achieve the continuous shading where the amplitude in each mesh is continuously varying. The proposed method enables the continuous shading, while maintaining fully analytic framework of the conventional method without any sacrifice in the precision. The proposed method can also be extended to enable fast update of the shading for different illumination directions and the ambient-diffuse reflection ratio based on Phong reflection model. The feasibility of the proposed method is confirmed by the numerical and optical reconstruction of the generated hologram.

Adhesive-Layer-Free and Double-Faced Nanotransfer Lithography for a Flexible Large-Area MetaSurface Hologram

“…Figure presents hologram morphologies, cross-sectional and large-area images, and other parameters. Holograms with different designs, widely studied and applied in the field of optics, − are mostly fabricated on glass and Si substrates using e-beam lithography. , In this work, we used the polygon-based computer-generated hologram (CGH) synthesis algorithm. − There are several design methods for CGH such as point clouds, depth-maps, and polygons. The polygon-based CGH is not very popular because of its difficulty in implementation, yet its rigor and accuracy in the modeling of holographic 3D scenes and algorithmic flexibility are very well recognized.…”

Recent progress in computer-generated holography for three-dimensional scenes

“…A linearly interpolated amplitude [17] or a textured pattern [18,19] are also used, however, for a more realistic representation of 3D objects with the given number of triangular meshes.…”

Polygon-based computer-generated holography: a review of fundamentals and recent progress [Invited]

“…The amplitude and phase function of each polygon can be encoded with the "surface function" introduced by Matsushima and Kondoh [25], and Matsushima and Nakahara [26], as Matsushima first investigated 3D surface objects with shade and texture [27]. Other examples include the works of Tang et al [28] and Park et al [29]. Inspired by the works of Matsushima et al, Ahrenberg et al [30] first presented algorithms for fast rendering of polygons directly in the angular spectrum domain based on an affine transformation.…”