• 제목/요약/키워드: Subdivision Modeling

검색결과 30건 처리시간 0.022초

Adaptive Subdivision for Geometry Coding of 3D Meshes (적응형 세분화를 이용한 3D 메쉬의 기하데이타 압축)

  • Lee Hae-Young
    • Journal of KIISE:Computer Systems and Theory
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    • 제33권8호
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    • pp.547-553
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    • 2006
  • We present a new geometry coding method for 3D meshes, an adaptive subdivision. Previous localized geometry coding methods have demonstrated better compression ratios than the global approach but they are considered hard to use in practice partly due to time - consuming quantization. Our new localized scheme replaces this quantization with an adaptive subdivision of the localized range. The deeper level a user chooses, the closer to the original the mesh will be restored. We also present an improved connectivity coder upon the current leading Angle-Analyzer's by applying a context-modeling. As a result, our new coder provides reliable and intuitive controls between bit-rate and distortion without losing efficiency.

An Improved Tracing algorithm for surface/surface intersection (곡면간의 교차곡선 계산을 위한 개선된 Tracing 알고리즘)

  • 조두연;이규열;임중현
    • Korean Journal of Computational Design and Engineering
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    • 제4권3호
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    • pp.269-283
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    • 1999
  • Surface/surface intersection is a common and important problem in geometric modeling and CAD/CAM. Several methods have been used to approach this problem. All possible intersection curves can be obtained by using the subdivision algorithm, while it requires a great deal of memory and is somewhat inefficient. The tracing algorithm is much faster than the subdivision algorithm, and can find points on the intersection curve sequentially. But, the tracing algorithm has some problems in the intersection curves on surface boundaries. In this paper, an Improved tracing algorithm that includes some ideas such as a new trace-terminating condition for the intersection curves on surface boundaries, detecting closed intersections and extension for composite surfaces is suggested. This algorithm consists of three step: generating state points for curve tracing, tracing intersection curves and sorting pieces of the intersection curves. The results of this algorithm and comparisons to the 'DESIGNBASE' and 'ACIS' system are presented.

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Procedural Modeling Algorithm for Traditional Stone Fence Creator (전통 돌담 생성을 위한 절차적 모델링 알고리즘)

  • Park, Kyeongsu
    • Journal of Digital Convergence
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    • 제11권8호
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    • pp.205-212
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    • 2013
  • In this paper, we present a procedural modeling algorithms to create Korean traditional stone fence using the fractal subdivision. The main process of the algorithm is to get the next step mesh by subdividing each triangle in the previous step triangular mesh. This process is repeated recursively. Dividing each triangle into four sub-triangles after choosing a random point on each side of the triangle and moving each vertices in the normal direction with random perturbations make the bumpy appearance of stone fences. In each step we remove flat vertices which does not influence the shape of the stone. The discrete curvature determines the flatness of a vertex. New triangles whose vertices are the vertices around the removed vertex are added to make a triangular mesh.

Creation Techniques of UV Nodes Needed in Maya 3D Modeling Convert (마야 3D모델링 변환에 필요한 UV노드 생성기법)

  • Kim, Hyun-Mun;Song, Teuk-Seob
    • Proceedings of the Korea Contents Association Conference
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    • 한국콘텐츠학회 2008년도 춘계 종합학술대회 논문집
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    • pp.534-538
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    • 2008
  • Maya currently is used form various area in 3D graphics. Maya provide that modeling methods are NURBs, Polygon, and Subdivision. There are special feature their modeling method. So we need to modeling convert. After modeling convert, there is no UV node. In this paper, we study creating techniques UV node which NURBs modeling convert Subdivsion modeling. Moreover, we present prototype implementation.

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A study on the Influence of Family-Friendly Program on Organizational Life and Job Commitment and Performance -Focusing on police officer organization-

  • Lee, Won-Hee;Eum, Seung-Sub;Kim, Woo-Hee;Lee, Yong-Joon
    • Journal of the Korea Society of Computer and Information
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    • 제22권12호
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    • pp.171-178
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    • 2017
  • Investigations into family-friendly company culture have been carried out for various companies and conglomerates. But there has never been such investigation for police organization, so this investigation is intended to see the effect on organizational commitment and job performance of the organization culture that makes use of family-friendly program for the police organization. To this end, how the internal factors of family-friendly organization culture affects organization commitment and job performance is empirically analyzed with structural equation modeling. And it is found that family-friendly program has significant effect on organizational life and welfare, and the welfare, in return, is found to have significant effect on job performance.

Development of a Spatial Subdivision Technique using BIM for Space Syntax Analysis of a Korean Traditional House (BIM을 이용한 전통 한옥의 공간구문 분석을 위한 공간분할기법 개발)

  • Jeong, Sang Kyu
    • KIEAE Journal
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    • 제10권3호
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    • pp.57-62
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    • 2010
  • To effectively use Building Information Modelling (BIM) dealing with semantic information including the entities of building components, the information about building components should be standardized. Like standardized modern buildings. in the past, Korean traditional houses were built according to strict procedures and formats. Therefore, if the Korean traditional house are modelled by using BIM,. not only the Korean traditional house of good quality will be built quickly and cheaply, but also spaces in the existing Korean traditional house will be easily analyzed. However, when analyzing spaces of the Korean traditional house using Space Syntax, some problems are caused in dividing outdoor space such as yard with unclear boundaries, unlike indoor space with clear boundaries surrounded by walls. These comes from the fact that researchers have subjectively divided a space in the house into convex spaces as units for Space Syntax analysis. Therefore, this study aims to develop an objective and rational spatial subdivision technique for Space Syntax analysis of a Korean traditional house modelled by using BIM. We could objectively and reasonably divide a Korean traditional house space into convex spaces by recognizing the building components in the house modelled in the form of Industry Foundation Classes(IFC). Depending on the connection of convex spaces allocated in the spatial subdivision technique, j-graph in Space Syntax could be drawn and the measurements of spatial configurations could be determinded. Through the developed technique, the social properties including the cultural and philosophical aspects of Korean people was identified by measuring the spatial configurations of Korean traditional house. The developed technique will serve as useful means to help architects to find an appropriate purpose of each space for sustainable architecture on the basis of the spatial and social relationships in buildings or urban systems.

A Compact and Efficient Polygonal Mesh Representation (간결하고 효율적인 폴리곤 메쉬의 표현 구조)

  • Park S. K.;Lee S. H.
    • Korean Journal of Computational Design and Engineering
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    • 제9권4호
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    • pp.294-305
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    • 2004
  • Highly detailed geometric models are rapidly becoming commonplace in computer graphics and other applications. These complex models, which is often represented as complex1 triangle meshes, mainly suffer from the vast memory requirement for real-time manipulation of arbitrary geometric shapes without loss of data. Various techniques have been devised to challenge these problems in views of geometric processing, not a representation scheme. This paper proposes the new mesh structure for the compact representation and the efficient handling of the highly complex models. To verify the compactness and the efficiency, the memory requirement of our representation is first investigated and compared with other existing representations. And then we analyze the time complexity of our data structure by the most critical operation, that is, the enumeration of the so-called one-ring neighborhood of a vertex. Finally, we evaluate some elementary modeling functions such as mesh smoothing, simplification, and subdivision, which is to demonstrate the effectiveness and robustness of our mesh structure in the context of the geometric modeling and processing.

Stability analysis of closely-spaced tunnel using RFEM (확률유한요소 해석에 의한 근접터널 안정성 분석)

  • Kim, Sang-Gyun
    • Journal of Korean Tunnelling and Underground Space Association
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    • 제10권4호
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    • pp.349-360
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    • 2008
  • In this paper, the modeling procedure of random field with an elasto-plastic finite element algorithm and probability of failure on closely-spaced tunnel were investigated. Local average subdivision (LAS) method which can generate discrete random variables fast and accurately as well as change the resolution in certain region was used. And correlated value allocating and weighted average method were suggested to implement geometrical characteristics of tunnel. After the probability of failure on the test problem was thoroughly investigated using random finite element method, the results were compared with the deterministic strength reduction factor method and single random variable method. Of particular importance in this work, is the conclusion that the probability of failure determined by simplified probabilistic analysis, in which spatial variability is ignored by assuming perfect correlation, can be estimated from the safety factor determined by strength reduction factor method. Also, single random variable method can lead to unconservative estimates of the probability of failure.

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A Study of Error Estimation and Adaptive Junction Subdivision for Electromagnetic Topology (전자기 토폴러지 기법에서의 오차 추정 및 적응적 정션 세분화 연구)

  • Park, Yoon-Mi;Chung, Young-Seek;Jung, Hyun-Kyo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • 제24권6호
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    • pp.623-632
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    • 2013
  • Electromagnetic topology simplifies a complex analysis area in accordance with electromagnetic coupling. And then electromagnetic topology divides the simplified continuous area into sub-areas and analyzes electromagnetic problems at the sub-areas. Therefore electromagnetic topology has a merit to analyze the electromagnetic coupling in large and complex systems, however simplified modeling technique can generate large errors. In this paper, power balance method is used to estimate errors and subdivide junctions in the electromagnetic topology. The method is applied to analyze conducted and radiated electromagnetic coupling in two kinds of cavity models. Improvement of accuracy was accomplished in accordance with junction subdivision. Moreover we could save computation time and memory comparing with FDTD results.

Development of Delaunay Triangulation Algorithm Using Oct-subdivision in Three Dimensions (3차원 8분할 Delaunay 삼각화 알고리즘 개발)

  • Park S.H.;Lee S.S.
    • Korean Journal of Computational Design and Engineering
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    • 제10권3호
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    • pp.168-178
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    • 2005
  • The Delaunay triangular net is primarily characterized by a balance of the whole by improving divided triangular patches into a regular triangle, which closely resembles an equiangular triangle. A triangular net occurring in certain, point-clustered, data is unique and can always create the same triangular net. Due to such unique characteristics, Delaunay triangulation is used in various fields., such as shape reconstruction, solid modeling and volume rendering. There are many algorithms available for Delaunay triangulation but, efficient sequential algorithms are rare. When these grids involve a set of points whose distribution are not well proportioned, the execution speed becomes slower than in a well-proportioned grid. In order to make up for this weakness, the ids are divided into sub-grids when the sets are integrated inside the grid. A method for finding a mate in an incremental construction algorithm is to first search the area with a higher possibility of forming a regular triangular net, while the existing method is to find a set of points inside the grid that includes the circumscribed sphere, increasing the radius of the circumscribed sphere to a certain extent. Therefore, due to its more efficient searching performance, it takes a shorer time to form a triangular net than general incremental algorithms.