High-speed signaling over high density interconnect on organic package substrates or silicon interposers offers an attractive solution to the off-chip bandwidth limitation problem faced in modern digital systems. In this paper, we describe a signaling system co-designed with the interconnect to take advantage of the characteristics of this environment to enable a high-speed, low area, and low-power die to die link.

Laminated packages, silicon interposer substrates, and special-purpose package- to-package interconnect, together with 3D stacking of silicon components enable systems with greatly improved computational power, memory capacity and bandwidth. These package options offer very high-bandwidth channels between chips on the same substrate. We employ ground-referenced single- ended signaling, a charge-pump transmitter, and a co-designed channel to provide communication between multiple chips on one package with high bandwidth per pin and low energy per bit.

We present PixelPie, a highly parallel geometric formulation of the Poisson-disk sampling problem on the graphics pipeline. Traditionally, generating a distribution by throwing darts and removing conflicts has been viewed as an inherently sequential process. In this paper, we present an efficient Poisson-disk sampling algorithm that uses rasterization in a highly parallel manner. Our technique is an iterative two step process. The first step of each iteration involves rasterization of random darts at varying depths. The second step involves culling conflicted darts.

Mobile computer-vision technology will soon become as ubiquitous as touch interfaces.

We introduce an energy efficient time-sharing pyramid pipeline architecture designed for multi-resolution image analysis in mobile computer vision. The time-sharing pipeline efficiently reduces the off-chip memory traffic by re-organizing the data storage and processing order of an image pyramid. We build a parameterized image pyramid hardware generator and successfully evaluate the overall pyramid design space.

Voxelized shadow volumes provide a discretized view-dependent representation of shadow volumes, but are limited to point or directional lights. We extend them to allow dynamic volumetric visibility from area light sources using imperfect shadow volumes. We show a coarser visibility sampling suffices for area lights. Combining this coarser resolution with a parallel shadow volume construction enables interactive rendering of dynamic volumetric shadows from area lights in homogeneous single-scattering media, at under 4x the cost of hard volumetric shadows.

We provide three analytical fits to the CIE x, y, and z color matching curves, commonly used in predictive and spectral renderers as an intermediate between light spectra and RGB colors. Any can replace the standard CIE curves, which come tabulated. Using tabulated curves can introduce typos, encourage crude simplifying approximations, or add opportunities to download curves from sources featuring inconsistent or incorrect data. Our analytic fits are simple to implement and verify.

We show how to efficiently compute 2D polyhedral bounds of the (elliptic) perspective projection of a 3D sphere that has been clipped to the near plane.

We introduce a novel Metropolis rendering algorithm that directly computes image gradients, and reconstructs the final image from the gradients by solving a Poisson equation. The reconstruction is aided by a low-fidelity approximation of the image computed during gradient sampling. As an extension of path-space Metropolis light transport, our algorithm is well suited for difficult transport scenarios. We demonstrate that our method outperforms the state-of-the-art in several well-known test scenes.

Spatially-varying reflectance and small geometric variations play a vital role in the appearance of real-world surfaces. Consequently, robust, automatic capture of such models is highly desirable; however, current systems require either specialized hardware, long capture times, user intervention, or rely heavily on heuristics. We describe an acquisition setup that utilizes only portable commodity hardware (an LCD display, an SLR camera) and contains no moving parts. In particular, a laptop screen can be used for illumination.