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... components of the normal vector on each triangle being updated every step. Fig. 1 shows the relative positions of two elements of the network at step k. This connguration is assumed consistent, i.e. there is no intersection between the two elements at this time. Consider now the connguration shown in Fig. 2 where node D has assumed a position at step k + 1 that has compromised in some way the connguration existing at step k and has produced an intersection. We are considering the triangle ABC as the colliding surface and node D as the colliding particle. The vectors X F and X D are deened by the directions that join the position of nodes ...
Context 2
... X F n and X D n are of opposite sign, then node D has crossed the plane during its path between step k and k + 1, or at least the edge DF of the triangle DEF intersects the plane of the triangle ABC. In fact if the collision involves two edges of diierent triangles, the connguration shown in Fig. 2 is still veriied. In this case, the node D does not intersect the triangle ABC during its path between the step k and the step k+1, but the edge DF still intersects the triangle ABC with an edge-to-edge collision connguration. ...
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Citations
... To solve this problem, three-dimensional (3D) pattern-making methods have been investigated by many researchers, both geometrically (Cho et al., 2005Cho et al., , 2006a Zhang et al., 2000) and mechanically (Imaoka et al., 1989). 3D body data has been used to make garment models and patterns by various 3D pattern-making systems (Watanabe, 1999; Bigliani et al., 2000; Kim and Park, 2004). In previous studies, researchers used body modelers to make an individual model (Cho et al., 2006a, b; Takatera and Kim, 2013; Daanen and Hong, 2008). ...
... To solve this problem, three-dimensional (3D) pattern-making methods have been investigated by many researchers, both geometrically (Cho et al., 2005Cho et al., , 2006a Zhang et al., 2000) and mechanically (Imaoka et al., 1989). 3D body data has been used to make garment models and patterns by various 3D pattern-making systems (Watanabe, 1999; Bigliani et al., 2000; Kim and Park, 2004). In previous studies, researchers used body modelers to make an individual model (Cho et al., 2006a, b; Takatera and Kim, 2013; Daanen and Hong, 2008). ...
Purpose
– The purpose of this paper is to produce an upper garment model for three-dimensional (3D) pattern making. This model will take into account ease allowance and silhouette, and will be used to propose a size-changing method.
Design/methodology/approach
– The authors used two real garment bodices with a surface suitable for pattern development. The garments were fitted to a designated dummy body and scanned. Using the scanned data, the authors made those upper garment basic models suitable for 3D pattern making. Using one model, the authors produced two bodice patterns, one with the original seam lines and the other with seam lines that differed from the original ones, and then compared them with the original jacket bodice. To construct garment models that were different in size from the basic model, the authors calculated multiplication factors of cross-sectional dimensions (in the front, back and lateral directions) between the basic garment and the actual garment shape worn on a body for each basic model. Using the multiplication factors, the authors made two different size garment models from two different size dummies for each basic model. The authors used these models to make patterns and garments.
Findings
– The reproduced jackets had similar shapes, silhouettes and ease allowances to the original jacket. Two garments of different sizes for each original jacket were made using the multiplication factors, and these garments also had similar silhouettes to the original jacket.
Research limitations/implications
– The implications of the work could be the new size-changing method.
Originality/value
– Using the modeling method, the authors were able to make complex new garment models that take into account ease allowance and silhouette. The ability to size these models up or down using multiplication factors could be a substitute for the grading method.
... Collision detection algorithms have been accelerated by various approaches based on bounding volume hierarchies, distance fields, image-space techniques, etc. One of the collision detection approaches is spatial partitioning proposed in [1], [2]. This approach splits 3D space into many regions in a pre- processing step. ...
In this paper, we propose an approach which combines hierarchical structures and particle systems for self-collision detection occurring in a deformable object. Numerous algorithms for collision detection have been proposed in computer graphics applications. Our algorithm exploits the efficiency of hierarchical structures to deal with many polygons, and particle systems because they can be used to extract colliding polygons. We have extended these two algorithms to deal with self-collision detection. The approach is split into two stages. Particles are distributed on the surface of a deformable object. Then, if the particles detect a possibility of a self-collision, hierarchical self-collision detection is started. The algorithm has been implemented on a square cloth model as an example of a deformable object. We show that the algorithm efficiently reduces self-collision detection redundancy, and yet precisely detects self-collision events.
... Some of them are designed for cloth animation. [20][21][22][23][24][25] In this paper, we concentrate on the accurate modeling of bending and buckling behavior, which is one of the most important tasks in the field of cloth simulation. ...
... If we want to model the behavior of thin flexible objects, the treatment of bending/buckling is very important. A lot of researches 10,12,14,15,23,26 have been dedicated to model cloth bending behavior effectively and efficiently. However, their investigations only concentrate on structural bending behavior which arises in the case of compressive in-plane deformation. ...
This paper addresses the problem of simulating the mechanical behavior of cloth in computer animation, which is very important and challenging. The micro-structure of woven fabrics leads to significantly different shear reaction from other sheet materials, which has been neglected in previous approaches of cloth simulation. Therefore, it is beneficial for cloth simulation to model the shear buckling and structural bending separately. We analyze the shear buckling yielded by the micro-structure of woven and the dynamic bending based on the thin-shell theory, and develop a compact implementation of the new model on mass-spring systems. Experimental results show that the animations generated using this technique are with wrinkles and folds appearing and vanishing in a more natural way than other approaches. Copyright © 2008 John Wiley & Sons, Ltd.
... The pioneering work of Terzopoulos et al.[1]provided a general physically based modeling method for elastic objects, which employs the finite-element and the finite-difference methods to solve the dynamic governing equations so that the deformation of objects like cloth, rubber, and metal can be stimulated. After the work of Terzopoulos et al.[1], many approaches have been dedicated to improve the simulation of cloth either in verisimilitude or in efficiency aspects, which include the methods by particle or spring-mass systems[2][3][4][5][6][7][8][9], the simulations by solid mechanics of continuum[1,[10][11][12][13][14][15], the numerical schemes to improve the computational stability and speed[6,8,[16][17][18][19], the collision handling approaches[20][21][22][23][24][25], and the realistic rendering of cloth materials[26]. However, none of the current existing approaches solves the problems of static bending or static buckling addressed in the following section, which make cloth simulation unrealistic and inaccurate. ...
Simulating the mechanical behavior of a cloth is a very challenging and important problem in computer animation. The models of bending in most existing cloth simulation approaches are taking the assumption that the cloth is little deformed from a plate shape. Therefore, based on the thin-plate theory, these bending models do not consider the condition that the current shape of the cloth under large deformations cannot be regarded as the approximation to that before deformation, which leads to an unreal static bending. [This paper introduces a dynamic bending model which is appropriate to describe large out-plane deformations such as cloth buckling and bending, and develops a compact implementation of the new model on spring-mass systems. Experimental results show that wrinkles and folds generated using this technique in cloth simulation, can appear and vanish in a more natural way than other approaches.]
... The adaptive refinement was incorporated into a cloth simulation system which include the following components: Baraff-Witkin's physics and integration, voxel-based cloth-cloth proximity detection (Eischen and Bigliani 2000), hierarchical bounding boxes for cloth-rigid proximity detection (Eischen and Bigliani 2000), and the collision response by Volino et al. (1995). Adaptation was performed before each simulation step. ...
... The adaptive refinement was incorporated into a cloth simulation system which include the following components: Baraff-Witkin's physics and integration, voxel-based cloth-cloth proximity detection (Eischen and Bigliani 2000), hierarchical bounding boxes for cloth-rigid proximity detection (Eischen and Bigliani 2000), and the collision response by Volino et al. (1995). Adaptation was performed before each simulation step. ...
Cloth animation is a very expensive process in terms of computational cost, due to the flexible nature of cloth objects. Since wrinkles and smooth areas co-exist commonly in cloth, it is tempting to reduce computational cost by avoiding redundant tessellation at the smooth areas. In this paper we present a method for dynamic adaptation of triangular meshes suitable for cloth simulation. A bottom-up approach is used for mesh refinement, which does not require precomputation and storage of multiresolution hierarchy. The hierarchy is constructed in runtime and allows reverting of the refinement locally. Local mesh refinement and simplification are triggered by curvature-induced criterion, where the curvature is estimated using methods of discrete differential geometry. The results presented are the realistic animation of garment worn by a walking mannequin generated with Baraff-Witkin type cloth solver enhanced with the mesh adaptation scheme.
... In addition, possibly colliding objects are identified by Sweep-and-Prune strategies [CLMP95]. As opposed to bounding volume hierarchies, regular grids partition the scene into voxels [BE99;ZY00]. Alternatively, graphics hardware [BWS98] can be employed to detect collisions in image-space, which was even investigated for cloth modelling [VSC01]. ...
In the animation of deformable objects, collision detection is crucial for the performance. Contrary to volumetric bodies, the accuracy requirements for the collision treatment of textiles are particularly strict because any over- lapping is visible. Therefore, we apply methods specically designed for deformable surfaces that speed up the collision detection. In this paper the efcienc y of bounding volume hierarchies is improved by adapted techniques for building and traversing these hierarchies. An extended set of heuristics is described that allows pruning of the hierarchy. Oriented ination of bounding volumes enables us to detect proximities with a minimum of extra cost.
... In addition, possibly colliding objects are identified by Sweep-and-Prune strategies [5]. As opposed to bounding volume hierarchies, regular grids partition the scene into voxels [4,32]. Alternatively, graphics hardware [1] can be employed to detect collisions in image-space, which was even investigated for cloth modelling [27]. ...
... If simpler bounding volumes are used, the detection speed decreases considerably. Tables (2,3,4,5) list some examples for non-optimal values, where "HU" and "CT" denote the computation times for the hierarchy update and the intrinsic collision test respectively. For the unoriented inflation an offset of ε close = 2cm was used to insure robust detection and response. ...
In the animation of deformable objects, collision detection and response are crucial for the performance. Contrary to volumetric bodies, the accuracy requirements for the collision treatment of textiles are particularly strict because any overlapping is visible. Therefore, we apply methods specifically designed for deformable surfaces that speed up the collision detection.
... He used a finite element method to simulate the cloth based on its mechanical properties, but in later years much simpler methods have been proposed. [2,4,6,14,15,16,21] use various methods to simulate clothes. The common factor of these methods is that they define the problem using a particle system and end up with a differential equation that has to be integrated. ...
... Trotzdem wurde in [EHH00] dieser Ansatz für ihre Raytracing-Methode verwendet, da er sich speziell zur Strahlverfolgung und folglich auch zur Bestimmung von Schnittpunkten der Partikel-Trajektorien mit den Objekten sehr gut eignet. In [BE99] ist ein rudimentäres System zur Voxelisierung mit einfachen Hashfunktionen beschrieben, das sehr schlechte Zeiten liefert. ...
