Light Fields for Near-eye Displays

The most important requirement to make any near-eye display successful is to provide a comfortable visual experience. This requirement has many boxes to check: having high resolution and wide field of view, being lightweight, having small form factor, and supporting focus cue. Like 3D TVs and movies, near-eye displays also need to solve the vergence and accommodation conflicts. In current Virtual Reality (VR) displays, the user fixates his focus on the fixed focal plane, and the disparity in the pre-processed content drives the eye to verge and creates a 3D sensation.

The Light Field Stereoscope

Over the last few years, virtual reality has re-emerged as a technology that is now feasible at low cost via inexpensive cellphone components. In particular, advances of high-resolution micro displays, low-latency orientation trackers, and modern GPUs facilitate extremely immersive experiences. To facilitate comfortable long-term experiences and wide-spread user acceptance, however, the vergence-accommodation conflict inherent to all stereoscopic displays will have to be solved.

Feedforward and Recurrent Neural Networks Backward Propagation and Hessian in Matrix Form

In this paper we focus on the linear algebra theory behind feedforward (FNN) and recurrent (RNN) neural networks. We review backward propagation, including backward propagation through time (BPTT). Also, we obtain a new exact expression for Hessian, which represents second order effects. We show that for t time steps the weight gradient can be expressed as a rank-t matrix, while the weight Hessian is as a sum of t2 Kronecker products of rank-1 and WTAW matrices, for some matrix A and weight matrix W.

Benjamin Klenk

Benjamin Klenk joined NVIDIA research in July 2017 after completing his PhD studies in Computer Engineering at the Ruprecht-Karls University in Heidelberg, Germany (defended with summa cum laude). His thesis focused on communication models for direct inter-GPU communication in which the GPU orchestrates the network traffic itself without the intervention of the CPU. He also holds a B.Eng. in Electrial Engineering from the Cooperative State Universtiy Mosbach, Germany and a M.Sc.

Michael Stengel

Michael joined Nvidia as a Research Scientist in 2017. His research interests include next generation augmented and virtual reality technology, perceptual real-time rendering, and hyperscale graphics systems. He obtained his PhD in 2016 from TU Braunschweig, Germany. His previous research on computational and augmented/virtual reality displays spans eye tracking, gaze-contingent and perceptual rendering, telepresence technology and immersive human-computer interaction at TU Braunschweig, TU Delft and VU Medical Center, Amsterdam.

Yaosheng Fu

Yaosheng Fu joined NVIDIA in September, 2017 as a member of the architecture research team. His current interests include computer architecture, memory systems and parallel computing. Yaosheng received his Ph.D. degree in Electrical Engineering at Princeton University, NJ in 2017 and B.S. in Electronic Engineering at Tsinghua University, China in 2010.

Near-eye Light Field Holographic Rendering with Spherical Waves for Wide Field of View Interactive 3D Computer Graphics

Holograms have high resolution and great depth of field allowing the eye to view a scene much like seeing through a virtual window. Unfortunately, computer generated holography (CGH) does not deliver the same promise due to hardware limitations under plane wave illumination and large computational cost. Light field displays have been popular due to their capability to provide continuous focus cue. However, light field displays suffer from the trade offs between spatial and angular resolution, and do not model diffraction.

Perceptually-Guided Foveation for Light Field Displays

A variety of applications such as virtual reality and immersive cinema require high image quality, low rendering latency, and consistent depth cues. 4D light field displays support focus accommodation, but are more costly to render than 2D images, resulting in higher latency. The human visual system can resolve higher spatial frequencies in the fovea than in the periphery. This property has been harnessed by recent 2D foveated rendering methods to reduce computation cost while maintaining perceptual quality.

SCNN: An Accelerator for Compressed-sparse Convolutional Neural Networks

Convolutional Neural Networks (CNNs) have emerged as a fundamental technology for machine learning. High performance and extreme energy efficiency are critical for deployments of CNNs, especially in mobile platforms such as autonomous vehicles, cameras, and electronic personal assistants. This paper introduces the Sparse CNN (SCNN) accelerator architecture, which improves performance and energy efficiency by exploiting the zero-valued weights that stem from network pruning during training and zero-valued activations that arise from the common ReLU operator.