scholarly journals Cuberille Implicit Surface Polygonization for ITK

2010 ◽  
Author(s):  
Dan Mueller
Keyword(s):  
Source Code ◽  
Implicit Surfaces ◽  
Implicit Surface ◽  
Surface Smoothing ◽  
Original Approach

This article describes an ITK implementation of the “cuberille” method for poloygonization of implicit surfaces. The method operates by dividing the surface into a number of small cubes called cuberilles. Each cuberille is centered at a pixel lying on the iso-surface and then quadrilaterals are generated for each face. The original approach is improved by projecting the vertices of each cuberille onto the implicit surface, smoothing the typical block-like resultant mesh. Source code and examples are provided to demonstrate the method.

Dual-Primal Mesh Optimization for Polygonized Implicit Surfaces With Sharp Features

2002 ◽  
Vol 2 (4) ◽  
pp. 277-284 ◽  
Author(s):  
Yutaka Ohtake ◽  
Alexander G. Belyaev
Keyword(s):  
Adaptive Mesh ◽  
Implicit Surfaces ◽  
Marching Cubes ◽  
Triangle Mesh ◽  
Implicit Surface ◽  
Weighted Vertex ◽  
Visualization Toolkit ◽  
Object Oriented Approach ◽  
Speed And Accuracy ◽  
Dual Mesh

A new method for improving polygonizations of implicit surfaces with sharp features is proposed. The method is based on the observation that, given an implicit surface with sharp features, a triangle mesh whose triangles are tangent to the implicit surface at certain inner triangle points gives a better approximation of the implicit surface than the standard Marching Cubes mesh [Lorensen, W.E., and Cline, H.E., 1987, Computer Graphics (Proceedings of SIGGRAPH ’87), 21(3), pp. 163–169] (in our experiments we use VTK Marching Cubes [Schroeder, W., Martin, K., and Lorensen, W., 1998, The Visualization Toolkit: An Object-Oriented Approach to 3-D Graphics, Prentice Hall]). First, given an initial triangle mesh, its dual mesh composed of the triangle centroids is considered. Then the dual mesh is modified such that its vertices are placed on the implicit surface and the mesh dual to the modified dual mesh is considered. Finally the vertex positions of that “double dual” mesh are optimized by minimizing a quadratic energy measuring a deviation of the mesh normals from the implicit surface normals computed at the vertices of the modified dual mesh. In order to achieve an accurate approximation of fine surface features, these basic steps are combined with adaptive mesh subdivision and curvature-weighted vertex resampling. The proposed method outperforms approaches based on the mesh evolution paradigm in speed and accuracy.

A Torus Patch Approximation Approach for Point Projection on Implicit Surfaces

2011 ◽  
Vol 346 ◽  
pp. 259-265
Author(s):  
Xiao Ming Liu ◽  
Lei Yang ◽  
Qiang Hu ◽  
Jun Hai Yong
Keyword(s):  
Iterative Algorithm ◽  
Geometric Modeling ◽  
Second Order ◽  
Implicit Surfaces ◽  
Implicit Surface ◽  
Approximation Approach ◽  
Initial Values ◽  
Point Projection

Point projection on an implicit surface is essential for the geometric modeling and graphics applications of it. This paper presents a method for computing the principle curvatures and principle directions of an implicit surface. Using the principle curvatures and principle directions, we construct a torus patch to approximate the implicit surface locally. The torus patch is second order osculating to the implicit surface. By taking advantage of the approximation torus patch, this paper develops a second order geometric iterative algorithm for point projection on the implicit surface. Experiments illustrate the efficiency and less dependency on initial values of our algorithm.

scholarly journals Tetrahedron-Based Porous Scaffold Design for 3D Printing

Designs ◽  
2019 ◽  
Vol 3 (1) ◽  
pp. 16 ◽  
Author(s):  
Ye Guo ◽  
Ke Liu ◽  
Zeyun Yu
Keyword(s):  
Minimal Surface ◽  
Porous Scaffold ◽  
3D Models ◽  
Structure Design ◽  
Implicit Surfaces ◽  
Implicit Surface ◽  
Periodic Minimal Surface ◽  
Triply Periodic ◽  
Hexahedral Meshes ◽  
Triply Periodic Minimal Surface

Tissue repairing has been the ultimate goal of surgery, especially with the emergence of reconstructive medicine. A large amount of research devoted to exploring innovative porous scaffold designs, including homogeneous and inhomogeneous ones, have been presented in the literature. The triply periodic minimal surface has been a versatile source of biomorphic structure design due to its smooth surface and high interconnectivity. Nonetheless, many 3D models are often rendered in the form of triangular meshes for its efficiency and convenience. The requirement of regular hexahedral meshes then becomes one of limitations of the triply periodic minimal surface method. In this paper, we make a successful attempt to generate microscopic pore structures using tetrahedral implicit surfaces. To replace the conventional Cartesian coordinates, a new coordinates system is built based on the perpendicular distances between a point and the tetrahedral faces to capture the periodicity of a tetrahedral implicit surface. Similarly to the triply periodic minimal surface, a variety of tetrahedral implicit surfaces, including P-, D-, and G-surfaces are defined by combinations of trigonometric functions. We further compare triply periodic minimal surfaces with tetrahedral implicit surfaces in terms of shape, porosity, and mean curvature to discuss the similarities and differences of the two surfaces. An example of femur scaffold construction is provided to demonstrate the detailed process of modeling porous architectures using the tetrahedral implicit surface.

scholarly journals Combination Constraints of Multiple Fields for Implicit Modeling of Ore Bodies

2021 ◽  
Vol 11 (3) ◽  
pp. 1321
Author(s):  
De-Yun Zhong ◽  
Li-Guan Wang ◽  
Jin-Miao Wang
Keyword(s):  
Surface Reconstruction ◽  
Experimental Results ◽  
Implicit Surfaces ◽  
Difference Operators ◽  
Implicit Function ◽  
Implicit Surface ◽  
Combination Rules ◽  
Ore Bodies ◽  
Pruning Strategy ◽  
Implicit Modeling

In this paper, we introduce combination constraints for modeling ore bodies based on multiple implicit fields interpolation. The basic idea of the method is to define a multi-labeled implicit function that combines different sub-implicit fields by the combination operations, including intersection, union and difference operators. The contribution of this paper resides in the application of combination of more general implicit fields with combination rules for the implicit modeling of ore bodies, such that the geologist can construct constraints honoring geological relationships more flexibly. To improve the efficiency of implicit surface reconstruction, a pruning strategy is used to avoid unnecessary calculations based on the hierarchical bounding box of the operation tree. Different RBF-based methods are utilized to study the implicit modeling cases of ore bodies. The experimental results of several datasets show that the combination constraints are useful to reconstruct implicit surfaces for ore bodies with mineralization rules involving multiple fields.

Medical Data and Mathematically Modeled Implicit Surface Real-Rime Visualization in Web Browsers

2021 ◽  
pp. 2250027
Author(s):  
Qi Zhang
Keyword(s):  
Surgical Simulation ◽  
Medical Training ◽  
Medical Data ◽  
Implicit Surfaces ◽  
Depth Information ◽  
Sampling Point ◽  
Processing Unit ◽  
Software Platform ◽  
Implicit Surface ◽  
Model Complex

Raycasting can display volumetric medical data in fine details and reveal crucial inner imaging information, while implicit surface is able to effectively model complex objects with high flexibility, combining these two rendering modalities together will provide comprehensive information of the scene and has wide applications in surgical simulation, image-guided intervention, and medical training. However, medical data rendering is based on texture depth at every sampling point, while mathematically modeled implicit surfaces do not have geometric information in texture space. It is a challenging task to visualize both physical scalar data and virtual implicit surfaces simultaneously. To address this issue, in this paper, we present a new dual-casting ray-based double modality data rendering algorithm and web-based software platform to visualize volumetric medical data and implicit surface in the same browser. The algorithm runs on graphics processing unit and casts two virtual rays from camera to each pixel on the display panel, where one ray travels through the mathematically defined scene for implicit surface rendering and the other one passes the 3D texture space for volumetric data visualization. The proposed algorithm can detect voxel depth information and algebraic surface models along each casting ray and dynamically enhance the visualized dual-modality data with the improved lighting model and transparency adjustment function. Moreover, auxiliary innovative techniques are also presented to enhance the shading and rendering features of interest. Our software platform can seamlessly visualize volumetric medical data and implicit surfaces in the same web browser over Internet.

Layered and ion implantation specimens as possible reference materials for the electron-probe microanalysis

1992 ◽  
Vol 50 (2) ◽  
pp. 1652-1653
Author(s):  
G. Remond ◽  
R.H. Packwood ◽  
C. Gilles ◽  
S. Chryssoulis
Keyword(s):  
Ion Implantation ◽  
Reference Materials ◽  
Analytical Techniques ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
X Ray ◽  
Spatially Resolved ◽  
Analytical Expressions ◽  
Original Approach ◽  
Depth Concentration

Merits and limitations of layered and ion implanted specimens as possible reference materials to calibrate spatially resolved analytical techniques are discussed and illustrated for the case of gold analysis in minerals by means of x-ray spectrometry with the EPMA. To overcome the random heterogeneities of minerals, thin film deposition and ion implantation may offer an original approach to the manufacture of controlled concentration/ distribution reference materials for quantification of trace elements with the same matrix as the unknown.In order to evaluate the accuracy of data obtained by EPMA we have compared measured and calculated x-ray intensities for homogeneous and heterogeneous specimens. Au Lα and Au Mα x-ray intensities were recorded at various electron beam energies, and hence at various sampling depths, for gold coated and gold implanted specimens. X-ray intensity calculations are based on the use of analytical expressions for both the depth ionization Φ (ρz) and the depth concentration C (ρz) distributions respectively.

SISTEM INFORMASI MANAJEMEN PENGARSIPAN BERBASIS FRAMEWORK CODE IGNITER UNTUK MENTERTIBKAN PELAYANAN SURAT MENYURAT

2019 ◽  
Vol 2 (1) ◽  
pp. 1-16
Author(s):  
Nana Suarna
Keyword(s):  
Source Code ◽  
Web Based

Seiring waktu, jumlah surat dalam sebuah perusahaan semakin hari makin banyak, sehingga muncul permasalahan dalam mengelolanya administrasi suarat, baik ketika dalam pencatatan surat maupun proses disposisi, serta pada saat pencarian arsip surat. Hampir sebagai besar surat yang ada di kantor-kantor masih disimpan dalam bentuk file-file yang masih bersifat manual, sehingga memungkinkan surat tersebut menunpuk, dan memerlukan waktu yang lama dalam pencarian dan pemrosesannya. Dengan dibangunnya  sistem manajemen pengarsipan bertujuan untuk mengatasi permasalahan-permasalahan tersebut di atas. Pemrograman  saat ini, baik desktop maupun web based, semakin marak  pengerjaannya menggunakan framework code igniter berbasis PHP. Framework CI memang dikembangkan untuk memudahkan dalam developing aplikasi dengan struktur  file source code-nya menggunakan pendekatan Models-Views-Controller (MVC) dan pemrograman berorientasi objek, oleh sebab itu penulis menggunakan CI dalam developing aplikasi ini. Aplikasi sistem manajemen surat dan pengarsipan ini dapat diakses dalam internal perusahaan web, yang bertujuan untuk memudahkan karyawan  dalam pengelolaan dan  mengaksesnya surat menyurat, selain itu aplikasi ini juga memberikan kemudahan dalam proses pencatatan surat,  disposisi, dan proses pencarian sehingga aplikasisi ini memiliki performa yang handal, mudah untuk di-maintenance dan dikembangkan lebih lanjut seiring perkembangan kebutuhan penggunanya.

Impact of Clone Refactoring on External Quality Attributes of Open Source Softwares

2018 ◽  
pp. 86-94
Author(s):  
Himanshi Vashisht ◽  
Sanjay Bharadwaj ◽  
Sushma Sharma
Keyword(s):  
Open Source ◽  
Internal Structure ◽  
Software Quality ◽  
Source Code ◽  
Quality Attributes ◽  
Software Component ◽  
External Quality ◽  
Code Refactoring ◽  
Observable Behaviour

Code refactoring is a “Process of restructuring an existing source code.”. It also helps in improving the internal structure of the code without really affecting its external behaviour”. It changes a source code in such a way that it does not alter the external behaviour yet still it improves its internal structure. It is a way to clean up code that minimizes the chances of introducing bugs. Refactoring is a change made to the internal structure of a software component to make it easier to understand and cheaper to modify, without changing the observable behaviour of that software component. Bad smells indicate that there is something wrong in the code that have to refactor. There are different tools that are available to identify and emove these bad smells. A software has two types of quality attributes- Internal and external. In this paper we will study the effect of clone refactoring on software quality attributes.

A practical approach on non-regular sampling and universal demosaicing of raw image sensor data

2020 ◽  
Vol 2020 (1) ◽  
pp. 91-95
Author(s):  
Philipp Backes ◽  
Jan Fröhlich
Keyword(s):  
Image Quality ◽  
Source Code ◽  
Image Sensor ◽  
Sensor Data ◽  
Color Filter ◽  
Lowpass Filter ◽  
Sampling Errors ◽  
Regular Sampling ◽  
Single Sensor ◽  
Similar Image Quality

Non-regular sampling is a well-known method to avoid aliasing in digital images. However, the vast majority of single sensor cameras use regular organized color filter arrays (CFAs), that require an optical-lowpass filter (OLPF) and sophisticated demosaicing algorithms to suppress sampling errors. In this paper a variety of non-regular sampling patterns are evaluated, and a new universal demosaicing algorithm based on the frequency selective reconstruction is presented. By simulating such sensors it is shown that images acquired with non-regular CFAs and no OLPF can lead to a similar image quality compared to their filtered and regular sampled counterparts. The MATLAB source code and results are available at: http://github. com/PhilippBackes/dFSR

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