Modern High-Performance Ray Casting toolkits, such as the Intel Embree library, which is a de facto industry standard, are a cornerstone of the high- performance levels seen in current CPU rendering. The purpose of Embree is an easy integration into professional image synthesis environments to ac- celerate rendering scenes with complex geometry, usually composed of many primitives. Unfortunately, Embree does not offer support for rendering con- structive solid geometry (CSG), solids composed of a manageable amount of primitive solids by using set operations. This is a significant drawback since CSG modeling is an intuitive and powerful option for describing com- plex geometry. In this thesis, we describe the integration of Embree into the predictive rendering system ART and propose a method for rendering CSG by combining the traversal of Embree's and ART's internal ray acceler- ation data structures. The tests we conducted with virtual scenes containing CSG not being constructed from triangle meshes showed that our method is competitive with the original ART renderer and often even faster. 1

The Embree/Butler scoring system served as criterion for ascertaining brain dysfunction on the protocols of 100 subjects--50 had been diagnosed by health professionals as having brain dysfunction, and 50 had been diagnosed as having no brain dysfunction. In comparing the hospital's diagnoses with those of the Embree/Butler method, the data strongly supported the hypothesis that the Embree/Butler scoring system did effectively discriminate (chi square of 77.99 < .01) between those with organic brain syndrome (or cerebral dysfunction) and those with psychiatric classification. A point-biserial correlation was used to distinguish the relationship between diagnosis and the score. A cutoff score of above 14 produced the least false-negative or false-positive evaluations.

Free-form surfaces and implicit surfaces must be tessellated before being rendered with rasterization techniques. However ray tracing provides the means to directly render such objects without the need to first convert into polygonal meshes. Since ray tracing can handle triangle meshes as well, the question of which method is most suitable in terms of performance, quality and memory usage is addressed in this thesis. Bézier surfaces and NURBS surfaces along with basic algebraic implicit surfaces are implemented in order to test the performance relative to polygonal meshes approximating the same objects. The parametric surfaces are implemented using an iterative Newtonian method that converges on the point of intersection using a bounding volume hierarchy that stores the initial guesses. Research into intersecting rays with parametric surfaces is surveyed in order to find additional methods that speed up the computation. The implicit surfaces are implemented using common direct algebraic methods. All of the intersection tests are implemented using the Embree ray tracing API as well as a SIMD library in order to achieve interactive framerates on a CPU. The results show that both Bézier surfaces and NURBS surfaces can achieve interactive framerates on a CPU using SIMD computation, with Bézier surfaces coming close to the performance of polygonal counterparts. The implicit surfaces implemented outperform even the simplest polygonal approximations.

Ray tracing is a popular algorithm used to simulate the behavior of light and is commonly used to render images with high levels of visual realism. Modern multicore CPUs and many-core GPUs can take advantage of the parallel nature of ray tracing to accelerate the rendering process and produce new images in real-time. For non-specialized hardware however, such implementations are often limited to low screen resolutions, simple scene geometry and basic graphical effects. In this work, a C++ framework was created to investigate how the ray tracing algorithm can be implemented and accelerated on the CPU and GPU, respectively. The framework is capable of utilizing two third-party ray tracing libraries, Intel’s Embree and NVIDIA’s OptiX, to ray trace various 3D scenes. The framework also supports several effects for added realism, a user controlled camera and triangle meshes with different materials and textures. In addition, a hybrid ray tracing solution is explored, running both libraries simultaneously to render subsections of the screen. Benchmarks performed on a high-end CPU and GPU are finally presented for various scenes and effects. Throughout these results, OptiX on a Titan X performed better by a factor of 2-4 compared to Embree running on an 8-core hyperthreaded CPU within the same price range. Due to this imbalance of the CPU and GPU along with possible interferences between the libraries, the hybrid solution did not give a significant speedup, but created possibilities for future research.