Region Decomposition And Adaptive Subdivision In Electromagnetic Computing

Electromagnetic scattering and radiation characteristics computational simulation of complex target have broad application value. In electromagnetic engineering applications, model mesh quality of these targets is very important to electromagnetic computing, it determines the adaptability, computing rate and accuracy of the corresponding electromagnetic calculation algorithm.Our work is mainly oriented electromagnetic computing, focus on format conversion of model, model region segmentation, and adaptive mesh subdivision.In format conversion of model part, we introduce two commonly used CAD model file format, IGES and STEP, and make a comparison between them. And we propose the reading algorithm of the formats and conversion algorithm.In model region segmentation part, we introduce several classic mesh segmentation algorithms first, including watershed method, skeleton extraction method. Then we improve the original algorithm, propose a curvature and region growing based algorithm of mesh segmentation. It can segment original mesh into several pieces by user chosen points.In adaptive mesh subdivision part, we first introduce some subdivision algorithm, for example, polygon subdivision, butterfly subdivision and its enhanced algorithm, SQRT3subdivision. Base on previous work, we propose an adaptive mesh subdivision algorithm base on Loop subdivision. We use flatness as the parameter that control subdivision. After adaptive subdivision, the flat region is sparse, rugged region is dense. So we decrease the number of facets without losing feature.At last, based on the implementation of above, we make corresponding modules. To better use these module, I integrate them into emX, an electromagnetic computing platform that developed by our group. Through case analysis, we verify the effectiveness of the algorithm and modules.