Recent work demonstrates that interactive ray tracing is possible on desktop systems, but there is still much debate as to how to most efficiently support advanced visual effects such as soft shadows, smooth freeform surfaces, complex shading, and animated scenes. With these challenges in mind, we reconsider the options for designing a rendering system and present Razor , a new software rendering architecture for distribution ray tracing designed to produce high-quality images with high performance on future single-chip many-core hardware. Razor includes two noteworthy capabilities: a set of techniques for quickly building the kd-tree acceleration structure on demand every frame from a scene graph and a system design that allows for crack-free multiresolution geometry with each ray independently choosing its geometry resolution. Razor's per-frame kd-tree build is designed to robustly handle arbitrarily scene animation, while its per-ray multiresolution geometry provides continuous level of detail driven by ray and path differentials. Razor also decouples shading from visibility computations using a two-phase shading scheme inspired by the REYES system, and caches tessellated representations of freeform surfaces at multiple levels of detail. We present experimental results gathered from a prototype system implemented on eight CPU cores, and discuss which aspects of the system are most successful and which would benefit from further investigation.

We present QuickBound, an algorithm for quickly determining whether a uniformly tessellated grid derived from a bilinear patch satisfies a maximum edge length threshold. Our approach generalizes the well-known technique of bounding the length of all horizontal and vertical edges in the uniformly tessellated grid by checking only a small, constant number of edges. We generalize this technique to apply to all diagonal edges. Our approach, called Quick-Bound, reduces the time complexity of determining whether an (m face x n face) grid satisfies the edge length threshold from O(mxn) to O(1). We provide a proof of correctness for QuickBound and also measure its effectiveness in a real-time bilinear patch visualizer.

Robotics researchers are often faced with real-time constraints, and for that reason algorithmic and implementation-level optimization can dramatically increase the overall performance of a robot. In this paper we illustrate how a substantial run-time gain can be achieved by taking advantage of the extended instruction sets found in modern processors, in particular the SSE1 and SSE2 instruction sets. We present an SSE version of Monte Carlo Localization that results in an impressive 9x speedup over an optimized scalar implementation. In the process, we discuss SSE implementations of atan, atan2 and exp that achieve up to a 4x speedup in these mathematical operations alone.

Significant improvement to visual quality for real-time 3D graphics requires modeling of complex illumination effects like soft-shadows, reflections, and diffuse lighting interactions. The conventional Z-buffer algorithm driven GPU model does not provide sufficient support for this improvement. This paper targets the entire graphics system stack and demonstrates algorithms, a software architecture, and a hardware architecture for real-time rendering with a paradigm shift to ray-tracing. The three unique features of our system called Copernicus are support for dynamic scenes, high image quality, and execution on programmable multicore architectures. The focus of this paper is the synergy and interaction between applications, architecture, and evaluation. First, we describe the ray-tracing algorithms which are designed to use redundancy and partitioning to achieve locality. Second, we describe the architecture which uses ISA specialization, multi-threading to hide memory delays and supports only local coherence. Finally, we develop an analytical performance model for our 128-core system, using measurements from simulation and a scaled-down prototype system. More generally, this paper addresses an important issue of mechanisms and evaluation for challenging workloads for future processors. Our results show that a single 8-core tile (each core 4-way multithreaded) can be almost 100% utilized and sustain 10 million rays/second. Sixteen such tiles, which can fit on a 240 mm2chip in 22 nm technology, make up the system and with our anticipated improvements in algorithms, can sustain real-time rendering. The mechanisms and the architecture can potentially support other domains like irregular scientific computations and physics computations.

While molecular visualization software has advanced over the years, today, most tools still operate on individual molecular structures with limited facility to manipulate large multicomponent complexes. We approach this problem by extending 3D image-based rendering via programmable graphics units, resulting in an order of magnitude speedup over traditional triangle-based rendering. By incorporating a biochemically sensitive level-of-detail hierarchy into our molecular representation, we communicate appropriate volume occupancy and shape while dramatically reducing the visual clutter that normally inhibits higher-level spatial comprehension. Our hierarchical, image based rendering also allows dynamically computed physical properties data (e.g. electrostatics potential) to be mapped onto the molecular surface, tying molecular structure to molecular function. Finally, we present another approach to interactive molecular exploration using volumetric and structural rendering in tandem to discover molecular properties that neither rendering mode alone could reveal. These visualization techniques are realized in a high-performance, interactive molecular exploration tool we call TexMol, short for Texture Molecular viewer.