• Proceedings of the Korean Society of Computer Information Conference
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• 2023.01a
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• pp.353-356
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• 2023

본 논문에서는 GPU 기반으로 옷감을 찢는 데 필요한 동적 재메쉬 기법에 대해서 제안한다. 일반적으로 메쉬를 파괴(Fracture)하거나 찢는 시뮬레이션에서는 안정적인 동역학 계산하는데 있어서 동적 재 메쉬과정에 매우 중요하며 이 과정이 계산양이 가장 크다. 본 논문에서는 GPU 친화적인 동적 메쉬 알고리즘을 새롭게 제안함으로써 옷감 찢기 시뮬레이션을 실시간으로 보여준다.

• Journal of Internet Computing and Services
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• v.18 no.3
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• pp.29-36
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• 2017

In these days, 3D dynamic simulation is closely related to many industries. In the past, physically-based 3D simulation was used mainly in the car crash or construction related fields, but it also plays an important role in movies or games today. Many mathematical computations are needed to represent the 3D object realistically, but it is difficult to process a large amount of calculations for simulation of application based on CPU in real-time. Recently, with the advanced graphic hardware and improved architecture, GPU can be utilized for the general purposes of computation function as well as graphic computation. Many approaches using GPU have been applied for various research fields. In this paper, we analyze the performance variation of two cloth simulation algorithms based on GPU according to the change of execution properties of GPU shaders in oder to optimize the performance of GPU-based cloth simulation. Cloth simulation is implemented by the spring centric algorithm and node centric algorithm with GPU parallel computing using compute shader of GLSL 4.3. We compare the performance of between these algorithms according to the change of the size and dimension of work group. The experiment is repeated to 10 times during 5,000 frames for each test and experimental results are provided by averaging of FPS. The experimental result shows that the node centric algorithm is executed in higher speed than the spring centric algorithm.

• Journal of the Korea Society of Computer and Information
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• v.9 no.4 s.32
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• pp.109-116
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• 2004

This paper describes a cloth simulation system for dressing 3D virtual human model with different pieces of clothing. The garments are constructed of cutting patterns seamed together. The system reads a body file and a cutting pattern file and produces a new model dressed with the specified garment by using a physical simulation based on a mass-spring model. For the realistic cloth simulation, it performs collision detection and response between triangles of the 3D human model and the garment. Because the number of triangles of a human model is very large. the collision detection and response requires a lot of time. To overcome this problem, we propose a pruning method which decreases the number of collision detection and response by a space-subdivision method. Experimental results show that the system produces realistic images and makes it possible to sew a garment around a virtual human body in several seconds.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.01a
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• pp.373-376
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• 2022

본 논문에서는 삼각형 메쉬 기반에서 옷감 시뮬레이션(Cloth simulation)에서 계산양이 큰 자기충돌(Self-collision) 처리를 GPU기반으로 가속화시킬 수 있는 방법에 대해 소개한다. CUDA기반으로 병렬 최적화하기 위해 본 논문에서는 1)재귀적으로 계산하여 충돌판정을 하는 BVH(Bounding volume hierarchy) 트리를 GPU기반에서 효율적으로 빌드, 업데이트, 트리 순회하는 방법을 제안하고, 2)삼각형 메쉬 기반에서는 중복되는 프리미티브(Primitive) 충돌검사를 최소화하기 위해 R-Triangle기법을 GPU에서 최적화 시키는 방법을 소개한다. 결과적으로 본 논문에서 제안하는 기법은 GPU 환경에서 옷감 시뮬레이션의 자기충돌과 객체충돌 처리를 빠르고 효율적으로 처리할 수 있도록 하였고, 다양한 장면에서 실험한 결과 모든 결과에서 빠른 시뮬레이션 결과를 얻을 수 있었다.

• Journal of the Korea Society of Computer and Information
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• v.29 no.8
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• pp.59-65
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• 2024

In this paper, we present a GPU-based acceleration of computationally intensive self-collision processing in triangular mesh-based cloth simulation. For Compute Unified Device Architecture (CUDA)-based parallel optimization, we propose 1) an efficient way to build, update, and traverse the Bounding Volume Hierarchy (BVH) tree on the GPU, and 2) optimize the Representative-Triangle (R-Triangle) technique on the GPU to minimize primitive collision checking in triangular mesh-based cloth simulations. As a result, the proposed method can handle self-collisions and object collisions of cloth simulation in GPU environment faster and more efficiently than CPU-based algorithms, and experiments on various scenes show that it can achieve simulation results that are 5x to 10x faster. Since the proposed method is optimized for BVH on GPU, it can be easily integrated into various algorithms and fields that utilize BVH.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.80-81
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• 2022

In this paper, the physical properties of actual fabric data are predicted using the Cusick drape system, which is a means of measuring the physical properties of fabrics. Using a three-dimensional volumetric system, the cloth data of the actual Cusick drape system is acquired in a three-dimensional point cloud format. Cusick drape simulation is performed using mesh data of the same shape and size as the fabric, and the physical parameters of the draped fabric most similar to the actual draped fabric are acquired.

• Journal of Korea Multimedia Society
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• v.11 no.4
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• pp.516-524
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• 2008

This paper presents a new modeling technique for the simulation of cloth specific characteristics with a set of hard constraints using an implicit constraint enforcement scheme. A conventional explicit Baumgarte constraint stabilization method has several defects. It requires users to pick problem-dependent coefficients to achieve fast convergence and has inherent stabilization limits. The proposed implicit constraint enforcement method is stable with large time steps, does not require problem dependent feed-back parameters, and guarantees the natural physics-based motion of an object. In addition, its computational complexity is the same as the explicit Baumgarte method. This paper describes a formulation of implicit constraint enforcement and provides a constraint error analysis. The modeling technique for complex components of cloth such as seams, buttons, sharp creases, wrinkles, and prevention of excessive elongation are explained. Combined with an adaptive constraint activation scheme, the results using the proposed method show the substantial enhancement of the realism of cloth simulations with a corresponding savings in computational cost.

• Journal of KIISE:Software and Applications
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• v.32 no.3
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• pp.181-191
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• 2005

This article describes a simplified mathematical model and the relevant numerical algorithm to simulate the draped cloth on virtual human body. The proposed algorithm incorporates an elliptical, or non-consecutive, method to simulate the cloth wrinkles on moving bodies without resorting to the result of the past time-steps of drape simulation. A global-local analysis technique was employed to decompose the drape of cloths into the global deformation and the local wrinkles that will be superposed linearly The global deformation is determined directly by the rotation and the translation of body parts to generate a wrinkle-free yet globally deformed shape of cloth. The local wrinkles are calculated by solving simple elliptical equations based on the orthogonality between conjugate harmonic functions representing the wrinkle amplitude and the direction of wrinkles. The proposed method requires no interpolative time frames even for discontinuous body postures. Standing away from the incremental approach of time integration in conventional methods, the proposed method yields a remarkable reduction of CPU time and an enhanced stability. Also, the transient motion of cloth could be achieved by interpolating between the deformations corresponding to each static posture.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.587-590
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• 2022

본 논문에서는 물리기반 옷감 시뮬레이션에 적합한 소리를 효율적으로 생성하기 위한 데이터 기반 합성 기법을 제안한다. 시뮬레이션에서 소리를 표현하는 방법은 크게 생성과 합성이 있지만, 합성은 실시간 애플리케이션에서 활용이 가능하기 때문에 인터랙티브한 환경에서 자주 활용되고 있다. 하지만, 데이터에 의존하기 때문에 원하는 장면에 부합하는 사운드를 합성하기는 어려우며, 기존 방법은 한 방향으로만 사운드 데이터를 검색하기 때문에 불연속으로 인한 끊김 현상이 발생한다. 본 논문에서는 양방향 사운드 합성 기법을 제시하며, 이를 통해 불연속적으로 합성되는 사운드 결과를 효율적으로 개선될 수 있음을 보여준다.

• Journal of Internet Computing and Services
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• v.19 no.6
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• pp.53-62
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• 2018

As the performance of computer hardware has been increased in recent years, more realistic computer generated objects can be created and presented in personal computers and portable digital devices as well. For this reason, digital contents, including computer graphics, require virtual objects that are more realistic and representable in real-time on various devices, thus it requires more computational costs. In order to support the production of contents including computer graphics, games, and animations on multi-platform, Unity or unreal engines are mainly used. To represent more realistic behavior of virtual objects in a simulation, a virtual object must collide with other virtual objects and present the plausible interaction, as in the real world. However, such dynamic simulation requires a large amount of computational cost, and most portable devices cannot provide these dynamic simulations in real-time. In this paper, we proposed a GPGPU computation based dynamic cloth simulation to represent collision and response with spherical object in real-time. We believe that the proposed method can be useful for readily producing realistic digital contents.