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The introduction of standardized APIs for ray tracing, together with hardware acceleration, opens up possibilities for physically based lighting in real-time rendering. Light importance sampling is one of the fundamental operations in light transport simulations, applicable to both direct and indirect illumination. This chapter describes a bounding volume hierarchy data structure and associated sa
While each new generation of processors gets larger caches and more compute power, external memory bandwidth capabilities increase at a much lower pace. Additionally, processors are equipped with wide vector units that require low instruction level divergence to be efficiently utilized. In order to exploit these trends in ray tracing, we present an alternative to traditional depth-first ray traver
We propose a generalized approach to decoupling shading from visibility sampling in graphics pipelines, which we call decoupled sampling. Decoupled sampling enables stochastic supersampling of motion and defocus blur at reduced shading cost, as well as controllable or adaptive shading rates which trade off shading quality for performance. It can be thought of as a generalization of multisample ant
In this paper, we present a new color buffer compression algorithm for floating-point buffers. It can operate in either an approximate (lossy) mode or in an exact (lossless) mode. The approximate mode is error-bounded and the amount of introduced accumulated error is controlled via a few parameters. The core of the algorithm lies in an efficient representation and color space transform, followed b
A fundamental part of many computer algorithms involves traversing a binary tree. One notable example is traversing a space-partitioning acceleration structure when computing ray-traced images. Traditionally, the traversal requires a stack to be temporarily stored for each ray, which results in both additional storage and memory-bandwidth usage. We present a novel algorithm for traversing a binary
This paper presents a new method, based on constraint programming, for modeling and solving scheduling and instruction selection for processors extended with a functionally reconfigurable cell fabric. Our method models parallel reconfigurable architectures, the selection of application specific computational patterns and application scheduling. It takes also into account architectural constraints.
This column examines the texture cache, an essential component of modern GPUs that plays an important role in achieving real-time performance when generating realistic images. GPUs have many components and the texture cache is only one of them. But it has a real impact on the performance of the GPU if rasterization and memory tiling are set up correctly.
Cylinder pressure sensors provide detailed information on the diesel engine combustion process. This paper presents a method to use cylinder-pressure data for prediction of engine emissions by exploiting data-mining techniques. The proposed method uses principal component analysis to reduce the dimension of the cylinder-pressure data, and a neural network to model the nonlinear relationship betwee
Cavitation is common in high-pressure homogenizers, and has severe negative effects such as noise and mechanical wear, but may also have a beneficial effect in promoting fragmentation. Greater knowledge concerning cavitation in the homogenizer valve is thus important in optimizing the design and utilization of emulsification equipment. The aim of this study was to locate the region of cavitation a
We propose a powerful hardware architecture for pixel shading, which enables flexible control of shading rates and automatic shading reuse between triangles in tessellated primitives. The main goal is efficient pixel shading for moderately to finely tessellated geometry, which is not handled well by current GPUs. Our method effectively decouples the cost of pixel shading from the geometric complex
Computer generated imagery is used in a wide range of disciplines, each with different requirements. As an example, real-time applications such as computer games have completely different restrictions and demands than offline rendering of feature films. A game has to render quickly using only limited resources, yet present visually adequate images. Film and visual effects rendering may not have st
Hierarchical depth culling is an important optimization, which is present in all modern high performance graphics processors. We present a novel culling algorithm based on a layered depth representation, with a per-sample mask indicating which layer each sample belongs to. Our algorithm is feed forward in nature in contrast to previous work, which rely on a delayed feedback loop. It is simple to i
From a control design point of view, modern diesel engines are dynamic, nonlinear, MIMO systems. This paper presents a method to find low-complexity black-box dynamic models suitable for model predictive control (MPC) of NOx and soot emissions based on on-line emissions measurements. A four-input-five-output representation of the engine is considered, with fuel injection timing, fuel injection dur
The aim of this study was to find models for turbulent fragmenting forces in the high-pressure homogeniser from data available in Computational Fluid Dynamics (CFD) simulations with Reynolds Averaged Navier Stokes (RANS) turbulence models. In addition to the more common RANS k-epsilon turbulence models, a Multi-scale k-epsilon model was tested since experimental investigations of the geometry impl
NURBS (Non-uniform rational B-splines) surfaces are one of the most useful primitives employed for high quality modeling in CAD/CAM tools and graphics software. Since direct evaluation of NURBS surfaces on the GPU is a highly complex task, the usual approach for rendering NURBS is to perform the conversion into Bezier surfaces on the CPU, and then evaluate and tessellate them on the GPU. In this p
We present two novel culling tests for rasterization of simultaneous depth of field and motion blur. These tests efficiently reduce the set of xyuvt samples that need to be coverage tested within a screen space tile. The first test finds linear bounds in ut - and vt -space using a separating line algorithm. We also derive a hyperplane in xyuvt - space for each triangle edge, and all samples outside
This paper presents the elaboration of an experimentally validated model of a continuous cross-flow atomic layer deposition (ALD) reactor with temporally separated precursor pulsing encoded in the Modelica language. For the experimental validation of the model, in situ quartz crystal microbalance (QCM) diagnostics was used to yield submonolayer resolution of mass deposition resulting from thin fil
