Zhong Chongli, Sang Xinzhu, Yan Binbin, Li Hui, Chen Duo, Qin Xiujuan
Opt Express. 2022 Oct 24;30(22):40087-40100. doi: 10.1364/OE.474644.
Holographic display is an ideal technology for near-eye display to realize virtual and augmented reality applications, because it can provide all depth perception cues. However, depth performance is sacrificed by exiting computer-generated hologram (CGH) methods for real-time calculation. In this paper, volume representation and improved ray tracing algorithm are proposed for real-time CGH generation with enhanced depth performance. Using the single fast Fourier transform (S-FFT) method, the volume representation enables a low calculation burden and is efficient for Graphics Processing Unit (GPU) to implement diffraction calculation. The improved ray tracing algorithm accounts for accurate depth cues in complex 3D scenes with reflection and refraction, which is represented by adding extra shapes in the volume. Numerical evaluation is used to verify the depth precision. And experiments show that the proposed method can provide a real-time interactive holographic display with accurate depth precision and a large depth range. CGH of a 3D scene with 256 depth values is calculated at 30fps, and the depth range can be hundreds of millimeters. Depth cues of reflection and refraction images can also be reconstructed correctly. The proposed method significantly outperforms existing fast methods by achieving a more realistic 3D holographic display with ideal depth performance and real-time calculation at the same time.
全息显示是近眼显示实现虚拟现实和增强现实应用的理想技术，因为它可以提供所有深度感知线索。然而，现有的用于实时计算的计算机生成全息图（CGH）方法牺牲了深度性能。本文提出了体表示法和改进的光线追踪算法，用于生成具有增强深度性能的实时CGH。使用单快速傅里叶变换（S-FFT）方法，体表示法计算负担低，并且对于图形处理单元（GPU）实现衍射计算效率高。改进的光线追踪算法考虑了具有反射和折射的复杂3D场景中的精确深度线索，这通过在体中添加额外形状来表示。数值评估用于验证深度精度。实验表明，所提出的方法可以提供具有精确深度精度和大深度范围的实时交互式全息显示。具有256个深度值的3D场景的CGH以30帧每秒的速度计算，深度范围可达数百毫米。反射和折射图像的深度线索也可以正确重建。所提出的方法通过同时实现具有理想深度性能的更逼真的3D全息显示和实时计算，显著优于现有的快速方法。
