Taku Itoh^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.31, No.4, pp. 1-1, 2024, DOI:10.32604/icces.2024.012260

Abstract In meshless methods, although elements constructing an analysis domain are not required, the domain should be represented in some way, instead. A scalar field g(x), that contains the analysis domain, is sometimes employed, and the boundary of analysis domain is represented as an implicit surface, g(x) = 0. In this study, we consider generating an implicit surface from scattered points on the surface of an object. The scattered points are obtained by a three-dimensional scanning device. To generate g(x), field values f_ijk on N3 uniform grid points x_ijk are required. Although the field values f_ijk have been… More >

Jiayu Ren^1,*, Susumu Nakata²

CMES-Computer Modeling in Engineering & Sciences, Vol.141, No.2, pp. 1033-1046, 2024, DOI:10.32604/cmes.2024.054238 - 27 September 2024

Abstract Three-dimensional surfaces are typically modeled as implicit surfaces. However, direct rendering of implicit surfaces is not simple, especially when such surfaces contain finely detailed shapes. One approach is ray-casting, where the field of the implicit surface is assumed to be piecewise polynomials defined on the grid of a rectangular domain. A critical issue for direct rendering based on ray-casting is the computational cost of finding intersections between surfaces and rays. In particular, ray-casting requires many function evaluations along each ray, severely slowing the rendering speed. In this paper, a method is proposed to achieve direct More >

Jiayu Ren^1,*, Yoshihisa Fujita², Susumu Nakata²

CMES-Computer Modeling in Engineering & Sciences, Vol.136, No.3, pp. 2111-2125, 2023, DOI:10.32604/cmes.2023.025970 - 09 March 2023

Abstract Implicit surface generation based on the interpolation of surface points is one of the well-known modeling methods in the area of computer graphics. Several methods for the implicit surface reconstruction from surface points have been proposed on the basis of radial basis functions, a weighted sum of local functions, splines, wavelets, and combinations of them. However, if the surface points contain errors or are sparsely distributed, irregular components, such as curvature-shaped redundant bulges and unexpectedly generated high-frequency components, are commonly seen. This paper presents a framework for restoring irregular components generated on and around surfaces. More >

Taku Itoh¹, Susumu Nakata²

CMES-Computer Modeling in Engineering & Sciences, Vol.107, No.3, pp. 187-199, 2015, DOI:10.3970/cmes.2015.107.187

Abstract To speed up generating a scalar field g(x) based on a piecewise polynomial, a new method for determining field values that are indispensable to generate g(x) has been proposed. In the proposed method, an intermediate for generating g(x) does not required, i.e., the field values can directly be determined from given point data. Numerical experiments show that the computation time for determining the field values by the proposed method is about 10.4–12.7 times less than that of the conventional method. In addition, on the given points, the accuracy of g(x) obtained by using the proposed More >

Raju R. Namburu¹, Eric R. Mark, Jerry A. Clarke

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.5, pp. 443-454, 2004, DOI:10.3970/cmes.2004.005.443

Abstract Computational electromagnetic (CEM) simulations of full-range military vehicles play a critical role in enhancing the survivability and target recognition of combat systems. Modeling of full-range military systems subjected to high frequencies may involve generating large-scale meshes, solving equations, visualization, and analysis of results in the range of billions of unknowns or grid points. Hence, the overall objective of this research is to develop and demonstrate a scalable CEM software environment to address accurate prediction of radar cross sections (RCS) for full- range armored vehicles with realistic material treatments and complex geometric configurations. A software environment… More >