Diffusion theory allows the production of realistic skin renderings. The dipole and multipole models allow for solving challenging diffusion-theory equations efficiently. By using texture-space diffusion, a Gaussian-b...
详细信息
Diffusion theory allows the production of realistic skin renderings. The dipole and multipole models allow for solving challenging diffusion-theory equations efficiently. By using texture-space diffusion, a Gaussian-based approximation, and programmable graphics hardware, developers can create real-time, photorealistic skin renderings. Performing this diffusion in screen space offers advantages that make diffusion approximation practical in scenarios such as games, where having the best possible performance is crucial. However, unlike the texture-space counterpart, the screen-space approach can't simulate transmittance of light through thin geometry; it yields unrealistic results in those cases. A new transmittance algorithm turns the screen-space approach into an efficient global solution, capable of simulating both reflectance and transmittance of light through a multilayered skin model. The transmittance calculations are derived from physical equations, which are implemented through simple texture access. The method performs in real time, requiring no additional memory usage and only minimal additional processing power and memory bandwidth. Despite its simplicity, this practical model manages to reproduce the look of images rendered with other techniques (both offline and real time) such as photon mapping or diffusion approximation.
The power consumption models of mobile application processors have emerged as key objects of interest following the tremendous growth in mobile device production given that such consumption is an important factor in t...
详细信息
The power consumption models of mobile application processors have emerged as key objects of interest following the tremendous growth in mobile device production given that such consumption is an important factor in the graphics performance of mobile technologies. Conventionally, the performance of the graphics processing units (GPUs) depends critically on texture mapping units, which is why the number of such GPU components and texture fill rates value prominently whenever the GPU performance is evaluated. Our previous work has established a model to predict maximum performance based on unified shaders. By extending the work, this paper developed a practically applicable GPU performance prediction model on the basis of texture mapping performance. The effects of increased texture mapping units on unified shader performance and GPU efficiency were examined, and a performance prediction model based on the number of frames per second (FPS) was constructed. For these purposes, a benchmark related to texture mapping units was formulated and the experiments were conducted to determine utilization factors that are relevant to GPU performance and efficiency. The final stage in model construction involved establishing a relationship between the previously investigated utilization factors and relevant resources that are consumed during graphics processing. The experimental results showed that the proposed prediction model produced an average error rate of 5.77%.
This study focuses on fast and robust outlier matches removal strategy to improve the efficiency and precision of initial alignment and further the quality of pairwise registration. Starts from the point matches obtai...
详细信息
This study focuses on fast and robust outlier matches removal strategy to improve the efficiency and precision of initial alignment and further the quality of pairwise registration. Starts from the point matches obtained via feature detecting and matching, the distance disparity matrix derived from Euclidean invariants of rigid transformation is introduced, based on which a fast and effective pruning method is proposed to eliminate the outlier correspondences, especially the sharp ones. Then, the remaining matches are sent into the enhanced least-square backward method to estimate an initial transformation in lesser attempts. Since most of the outliers are rejected, presented backward method could provide a finer alignment to input point clouds in higher efficiency than existing methods, and the following refining procedure converges to a more precise registration consuming fewer iterations, which have been proved in designed experiments. The thresholds employed in the pipeline are all automatically determined according to the actual resolution of input point clouds. Users are just required to control the error precision through a scale factor, in which way the inaccuracy and inconvenience of manually threshold defining are avoided.
Aspects of digital video transmission systems are incorporated into a low-cost equipment for engineering training purposes. The equipment described simulates a p.c.m. monochrome video link and incorporates scrambling,...
详细信息
Aspects of digital video transmission systems are incorporated into a low-cost equipment for engineering training purposes. The equipment described simulates a p.c.m. monochrome video link and incorporates scrambling, automatic word framing and error concealment, Word framing and the problem of error extension are discussed in some detail.
An efficient parallel algorithm to obtain maximum matchings in convex bipartite graphs is developed. This algorithm can be used to obtain efficient parallel algorithms for several scheduling problems. Some examples ar...
详细信息
An efficient parallel algorithm to obtain maximum matchings in convex bipartite graphs is developed. This algorithm can be used to obtain efficient parallel algorithms for several scheduling problems. Some examples are: job scheduling with release times and deadlines; scheduling to minimize maximum cost; and preemptive scheduling to minimize maximum completion time.
The surface profile histories of gentle spilling breakers generated mechanically with a dispersive focusing technique are studied experimentally. Froude-scaled generation conditions are used to produce waves with thre...
详细信息
The surface profile histories of gentle spilling breakers generated mechanically with a dispersive focusing technique are studied experimentally. Froude-scaled generation conditions are used to produce waves with three average frequencies: f(0) = 1.42, 1.26, and 1.15 Hz. At each frequency, the strength of the breaker is varied by varying the overall amplitude of the wavemaker motion. It is found that in all cases the beginning of the breaking process is marked by the formation of a bulge in the profile at the crest on the forward face of the wave. The leading edge of this bulge is called the toe. As the breaking process continues, the bulge becomes more pronounced while the toe remains in nearly a fixed position relative to the crest. Capillary waves form ahead of the toe. At a time of about 0.1/f(0) after the bulge first becomes visible, the toe begins to move down the face of the wave and very quickly accelerates to a constant velocity which scales with the wave crest speed. During this phase of the breaker evolution, the surface profile between the toe and the crest develops ripples which eventually are left behind the wave crest. It is found that the height of the toe above the mean water level scales with the nominal wavelength lambda(0) = g/(2 pi f(0)(2)) of the breaker, while the size and shape of the bulge and the length of the capillary waves ahead of the toe are independent of f(0).
We propose a new approach for computing in an efficient way polygonal approximations of generalized 2D/3D Voronoi diagrams. The method supports distinct site shapes ( points, line-segments, curved-arc segments, polygo...
详细信息
We propose a new approach for computing in an efficient way polygonal approximations of generalized 2D/3D Voronoi diagrams. The method supports distinct site shapes ( points, line-segments, curved-arc segments, polygons, spheres, lines, polyhedra, etc.), different distance functions (Euclidean distance, convex distance functions, etc.) and is restricted to diagrams with connected Voronoi regions. The presented approach constructs a tree ( a quadtree in 2D/an octree in 3D) which encodes in its nodes and in a compact way all the information required for generating an explicit representation of the boundaries of the Voronoi diagram approximation. Then, by using this hierarchical data structure a reconstruction strategy creates the diagram approximation. We also present the algorithms required for dynamically maintaining under the insertion or deletion of sites the Voronoi diagram approximation. The main features of our approach are its generality, efficiency, robustness and easy implementation.
This article examines why innovations such as the Sony EyeToy and Nintendo Wii have been so successful and discusses the research opportunities presented by the latest commercial push for spatial 3D interaction in games.
This article examines why innovations such as the Sony EyeToy and Nintendo Wii have been so successful and discusses the research opportunities presented by the latest commercial push for spatial 3D interaction in games.
The Huffman code is a noiseless source coding method for images, video, and other applications. For applications in graphic computers, image and video composition, high-definition television (HDTV), and optical fiber ...
详细信息
The Huffman code is a noiseless source coding method for images, video, and other applications. For applications in graphic computers, image and video composition, high-definition television (HDTV), and optical fiber networks, Huffman-coded images need to be reconstructed at a high throughput rate. Part I [I] of this paper already showed several architectural and architecture-specific optimization techniques. However, due to the recursion within the reconstruction algorithm, the achievable throughput rate for a given decoding architecture in a given IC technology Is limited. In this part of the paper, we propose various concurrent decoding methods to relax the throughput limit by using parallel or pipelined hardware. These methods are simple, effective, flexible, and applicable to general decoder architectures. Unlimited concurrency can be achieved at the expense of additional latency, the overhead Is low, and the complexity increases linearly with the throughput improvement. We believe that the proposed methods and architectures make It possible to reconstruct arbitrarily high resolution Huffman-coded images and video in real time with current electronics.
This new GPU-based algorithm can compute ambient occlusion to inexpensively approximate global-illumination effects in real-time systems and games. The algorithm is based on a novel interpretation of ambient occlusion...
详细信息
This new GPU-based algorithm can compute ambient occlusion to inexpensively approximate global-illumination effects in real-time systems and games. The algorithm is based on a novel interpretation of ambient occlusion that measures the relative volume of the visible part of the surface's tangent sphere.
暂无评论