A hidden line removal algorithm for bi parametric surfaces is presented and illustrated by some experimental results. The enclosure test is done using area coordinates. A technique of moving box of encirclement is p...A hidden line removal algorithm for bi parametric surfaces is presented and illustrated by some experimental results. The enclosure test is done using area coordinates. A technique of moving box of encirclement is presented. It is found that the algorithm is of general purpose, requires minimal computer storage, has high accuracy and simplicity, and is very easy to be implemented on a computer.展开更多
Automatic recognition and interpretation of engineering drawing plays an important role in computer aided engineering. Detecting the positional relation between entities is an important topic in this research field. I...Automatic recognition and interpretation of engineering drawing plays an important role in computer aided engineering. Detecting the positional relation between entities is an important topic in this research field. In this paper the concepts of adjacent relativity and container window of drawing entities were proposed. By means of container window, the adjacent irrelative entities can be detected quickly and effectively, which speeds up the process of adjacent relativity detection. Meanwhile, the algorithm of adjacent relativity detection was discussed.展开更多
This paper advances a new algorithm oriented to geometry modeling (GM) by using frame model. The elemental data structure of frame model is the vertex. This afeoithm provides a general and rapid method. By this way,we...This paper advances a new algorithm oriented to geometry modeling (GM) by using frame model. The elemental data structure of frame model is the vertex. This afeoithm provides a general and rapid method. By this way,we can link the vertices to construct the elemental frame and need not consider the topological relation among vertices which consist of the concrete entity. Then, we can combine the elemental frames to complete frame modeling by using aided-line method referring to concrete entity. We will discuss two keystones in the paper. Then we give a 3D geometry modeling example based on wire-frame model using the new algorithm.展开更多
This article discusses the disadvantages of current computer aided garment design system first, and then brings forward the frame of intelligent garment design system. Based on the analysis of the structure of the int...This article discusses the disadvantages of current computer aided garment design system first, and then brings forward the frame of intelligent garment design system. Based on the analysis of the structure of the intelligent system, it is pointed out that the intelligent pattern design system is the most important module of the whole system. The use of an expert system to realize the intelligent pattern design system is then proposed and the key technique of the system is discussed at last.展开更多
Mesh parameterization is one of the fundamental operations in computer graphics(CG) and computeraided design(CAD). In this paper, we propose a novel local/global parameterization approach, ARAP++, for singleand multi-...Mesh parameterization is one of the fundamental operations in computer graphics(CG) and computeraided design(CAD). In this paper, we propose a novel local/global parameterization approach, ARAP++, for singleand multi-boundary triangular meshes. It is an extension of the as-rigid-as-possible(ARAP) approach, which stitches together 1-ring patches instead of individual triangles. To optimize the spring energy, we introduce a linear iterative scheme which employs convex combination weights and a fitting Jacobian matrix corresponding to a prescribed family of transformations. Our algorithm is simple, efficient, and robust. The geometric properties(angle and area)of the original model can also be preserved by appropriately prescribing the singular values of the fitting matrix. To reduce the area and stretch distortions for high-curvature models, a stretch operator is introduced. Numerical results demonstrate that ARAP++ outperforms several state-of-the-art methods in terms of controlling the distortions of angle, area, and stretch. Furthermore, it achieves a better visualization performance for several applications, such as texture mapping and surface remeshing.展开更多
文摘A hidden line removal algorithm for bi parametric surfaces is presented and illustrated by some experimental results. The enclosure test is done using area coordinates. A technique of moving box of encirclement is presented. It is found that the algorithm is of general purpose, requires minimal computer storage, has high accuracy and simplicity, and is very easy to be implemented on a computer.
文摘Automatic recognition and interpretation of engineering drawing plays an important role in computer aided engineering. Detecting the positional relation between entities is an important topic in this research field. In this paper the concepts of adjacent relativity and container window of drawing entities were proposed. By means of container window, the adjacent irrelative entities can be detected quickly and effectively, which speeds up the process of adjacent relativity detection. Meanwhile, the algorithm of adjacent relativity detection was discussed.
文摘This paper advances a new algorithm oriented to geometry modeling (GM) by using frame model. The elemental data structure of frame model is the vertex. This afeoithm provides a general and rapid method. By this way,we can link the vertices to construct the elemental frame and need not consider the topological relation among vertices which consist of the concrete entity. Then, we can combine the elemental frames to complete frame modeling by using aided-line method referring to concrete entity. We will discuss two keystones in the paper. Then we give a 3D geometry modeling example based on wire-frame model using the new algorithm.
文摘This article discusses the disadvantages of current computer aided garment design system first, and then brings forward the frame of intelligent garment design system. Based on the analysis of the structure of the intelligent system, it is pointed out that the intelligent pattern design system is the most important module of the whole system. The use of an expert system to realize the intelligent pattern design system is then proposed and the key technique of the system is discussed at last.
基金supported by the National Natural Science Foundation of China(Nos.61432003,61572105,11171052,and 61328206)
文摘Mesh parameterization is one of the fundamental operations in computer graphics(CG) and computeraided design(CAD). In this paper, we propose a novel local/global parameterization approach, ARAP++, for singleand multi-boundary triangular meshes. It is an extension of the as-rigid-as-possible(ARAP) approach, which stitches together 1-ring patches instead of individual triangles. To optimize the spring energy, we introduce a linear iterative scheme which employs convex combination weights and a fitting Jacobian matrix corresponding to a prescribed family of transformations. Our algorithm is simple, efficient, and robust. The geometric properties(angle and area)of the original model can also be preserved by appropriately prescribing the singular values of the fitting matrix. To reduce the area and stretch distortions for high-curvature models, a stretch operator is introduced. Numerical results demonstrate that ARAP++ outperforms several state-of-the-art methods in terms of controlling the distortions of angle, area, and stretch. Furthermore, it achieves a better visualization performance for several applications, such as texture mapping and surface remeshing.
