November 27, 2017

Fast Gaze-Contingent Optimal Decompositions for Multifocal Displays


Our goal is to enable interactive optimal decomposition algorithms capable of driving a vergence- and accommodation-tracked multifocal testbed. Ultimately, such a testbed is necessary to establish the requirements for the practical use of multifocal displays, in terms of computational demand and hardware accuracy. To this end, we present an efficient algorithm for optimal decompositions, incorporating insights from vision science.

Oliver Mercier, Yusufu Sulai, Kevin Mackenzie, Marina Zannoli, James Hillis, Derek Nowrouzezahrai, Douglas Lanman
October 25, 2017

DodecaPen: Accurate 6DoF Tracking of a Passive Stylus

ACM Symposium on User Interface Software and Technology (UIST)

We propose a system for real-time six degrees of freedom (6DoF) tracking of a passive stylus that achieves sub-millimeter accuracy, which is suitable for writing or drawing in mixed reality applications.

Po-Chen Wu, Robert Wang, Kenrick Kin, Christopher Twigg, Shangchen Han, Ming-Hsuan Yang, Shao-Yi Chien
October 22, 2017

Deltille Grids for Geometric Camera Calibration

International Conference on Computer Vision (ICCV)

The recent proliferation of high resolution cameras presents an opportunity to achieve unprecedented levels of precision in visual 3D reconstruction. Yet the camera calibration pipeline, developed decades ago using checkerboards, has remained the de facto standard. In this paper, we ask the question: are checkerboards the optimal pattern for high precision calibration?

Hyowon Ha, Michal Perdoch, Hatem Alismail, In So Kweon, Yaser Sheikh
September 24, 2017

Propagation of Joint Space Quantization Error to Operational Space Coordinates and Their Derivatives

IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)

In this paper, we characterize encoder error in a robotic system. Given encoder specifications, robot kinematics, and discrete transfer functions mapping coordinates to their derivatives, we describe the propagation of quantization error on joint space coordinates to operational space coordinates, joint space coordinate derivatives, and operational space coordinate derivatives.

Nick Colonnese, Allison M. Okamura
July 31, 2017

Focal Surface Displays


We introduce focal surface displays to meet the challenge of vergence-accommodation conflict, augmenting conventional HMDs with a phase-only spatial light modulator (SLM) placed between the display screen and viewing optics. This SLM acts as a dynamic freeform lens, shaping synthesized focal surfaces to conform to the virtual scene geometry.

Nathan Matsuda, Alexander Fix, Douglas Lanman
July 30, 2017

Low-Cost 360 Stereo Photography and Video Capture


In this work, we describe a method that takes images from two 360â—¦ spherical cameras and synthesizes an omni-directional stereo panorama with stereo in all directions. Our proposed method has a lower equipment cost than camera-ring alternatives, can be assembled with currently available off-the-shelf equipment, and is relatively small and light-weight compared to the alternatives.

Kevin Matzen, Michael Cohen, Bryce Evans, Johannes Kopf, Richard Szeliski
June 6, 2017

Analysis of Effective Impedance Transmitted to the Operator in Position-Exchange Bilateral Teleoperation

IEEE World Haptics 2017

In this paper, we analyze the impedance transmitted to the operator in bilateral teleoperation including the effects of master and slave dynamics, local and communication time delay, low-pass filtering of the velocity estimate, and controller stiffness and damping, for three different environment dynamics: free, clamped, and a mass-damper-spring.

Nick Colonnese, Allison M. Okamura
May 30, 2017

International Image Sensors Workshop

International Image Sensor Workshop (IISW)

In this paper, we provide examples of some tracking and mapping functions of virtual reality sensors that illustrate the critical requirements and performance metrics. The sensor performance, form factor, power, and data bandwidth are the main challenges in a battery powered, always on VR devices.

Chiao Liu, Michael Hall, Renzo De Nardi, Nicholas Trail, Richard Newcombe