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Distribution and Autocorrelation of Internal Fields; The Chi Square Distribution
Published in Richard Holland, Richard St. John, Statistical Electromagnetics, 2020
Richard Holland, Richard St. John
Asomewhat less trivial application of this formalism is the log normal mapping of (0.1) onto (0, ∞). In this case, elg(u) is given by elg(u)=12πexp(−(lnu−μlg)2/(2σlg2))(σlgu)
Augmented Reality-Based Visualization for Echocardiographic Applications
Published in Terry M. Peters, Cristian A. Linte, Ziv Yaniv, Jacqueline Williams, Mixed and Augmented Reality in Medicine, 2018
Gabriel Hanssen Kiss, Cameron Lowell Palmer, Ole Christian Mjølstad, Håvard Dalen, Bjørn Olav Haugen, Hans Torp
V0 is the initial position of a vertex on the Zygote mesh, MLD is the local deformation for temporal alignment, and MDM is the mesh deformation matrix to align the Zygote mesh with the segmented left ventricle. Additionally, mesh clipping with a plane representing the ultrasound image plane is implemented to visualize the inner structures of the heart corresponding to the current slice plane. The fragment shader is a standard Gouraud shader, with normal mapping added to improve the appearance of the heart model by displaying fine details without the need for a high-resolution mesh.
Modified method of parallel-hierarchical network teaching based on population coding
Published in Waldemar Wójcik, Andrzej Smolarz, Information Technology in Medical Diagnostics, 2017
L.I. Timchenko, M. Zlepko, A. Smolarz, K. Gromaszek, B. Suleimenov, A. Kalizhanova
An approach of flow programming is suggested to program the GPU. This approach includes splitting a program into relatively small stages (core programs) that process data flow elements. Core programs go into shaders, and data flows go into textures in the GPU. A shader is a program performed in the GPU and processing the data flow. “Data flow” means information about the coordinates of polygon vertices, each vertex illumination, normal mapping, texture coordinates and so on, that permanently arrives in blocks to the shader program. A video processor receives outgoing information for all three vertices of the polygon. Having data on the three vertices, the GPU goes through all the pixels of a single polygon, while gradually changing (interpolating) vertex values from one vertex to another. A shader length is a memory space of the shader program. Considering that data arriving to the shader are random for the programmer, in a sense that the order in which the data will be sent to the shader is not preset, the shader program does not have any statistical or general variables; there is nothing similar to files or information storage between calls. Otherwise, the shader program is similar to a regular C program: there are input, output and time variables, standard functions, structures, arrays, cycles and conditional operators.
Parametric 3D simulations of spun yarns and fabrics
Published in The Journal of The Textile Institute, 2023
W. Deng, X. Wang, W. Ke, C. Wang, Z. Deng
Fabric structures close to real fabrics can be constructed based on mechanical collision simulation (Leaf et al., 2018). Especially, the yarn level simulation can generate more realistic patterns. Through this method, fabric texture close to the real one can be obtained, except in some details, such as yarn hairiness and the influence of yarn twist on the light and shade change of yarn surface (Figure 2 (a) and (b)). At present, in commercial advertisements and computer games, yarn twist is mainly simulated by rendering maps, which can greatly reduce the complexity of the model and the consumption of computing power, but this also limits the application scope of fabric models (Liu et al, 2023). Unreal Engine 5 (UE5) can use normal mapping to achieve the texture effect of yarn twisting (Figure 2(c) and (d)).
Geovisualization with immersive virtual environments in theory and practice
Published in International Journal of Digital Earth, 2019
Florian Hruby, Rainer Ressl, Genghis de la Borbolla del Valle
Bathymetry data was imported into UE as heightmap and subsequently converted into a 3D mesh. Information on benthic coverage (Figure 2) was then (temporarily) mapped onto the bathymetry mesh in order to distribute and allocate all 3D models correctly. Three methods of object distribution were adopted: As shown in Figure 2, almost half of the study area is covered by seagrass. For efficient usage of computing resources, normal mapping (Gortler 2012) was therefore applied to these areas. In addition, UE's SimpleGrassWind node was used to simulate the effect of wave movement on the seagrasses.Unlike seagrass, corals do not form extensive meadows but rather occur in compact colonies. To reflect this characteristic, several colonies were modeled based on photographic reference material and distributed (in accordance with Figure 2) within all relevant parts of the study area. Figure 4 shows an example of an original site and its VR replica.In addition to the stationary reef system coverage, we also included several fish and sea turtle species into the GeoIVE. The rigged models were distributed via path animation in the relevant parts of the ecosystems.
Editable texture map generation and optimization technique for 3D visualization presentation
Published in Computer-Aided Design and Applications, 2018
Tsung-Chien Wu, Jiing-Yih Lai, Watchama Phothong, Douglas W. Wang, Chao-Yaug Liao, Ju-Yi Lee
The mesh parameterization technique in computational geometry provides several practical applications. Sheffer et al. [16] and Hormann et al. [9] introduced and summarized several typical methods of mesh parameterization and its applications, e.g. texture mapping, normal mapping, detail transfer, morphing, mesh completion, editing, database, remeshing, and surface fitting. The available techniques for mesh parameterization can be divided into types relating to distortion minimization, fixed or free boundary, or numerical complexity. For distortion minimization, an objective function can be formulated in terms of angles, areas or distances, and it is minimized to yield the optimized mapping of the model from the 3D domain to the parametric domain (called UV domain hereafter). The fixed boundary can be obtained by a simple formulation, allowing for an easy solution, but, the distortion in parameterization is quite large. In contrast, the free boundary has less distortion in parameterization, but obtaining the solution is time-consuming in computation because the boundary is considered as part of the solution. Numerical complexity is divided into linear and nonlinear methods. The nonlinear method is complex and requires more computational time, but it yields less distortion in the result.