• Journal of the Korea Computer Graphics Society
• /
• v.11 no.4
• /
• pp.39-44
• /
• 2005

인터랙티브 컴퓨터 게임과 컴퓨터 애니메이션에서, 유관절체의 움직임을 직관적으로 제어하도록 하는 것은 어려운 문제로 인식되고 있다. 이런 분야에서는 대부분 움직임의 대상이 되는 캐릭터가 많은 관절로 연결되어 있는데, 이때 각 관절을 사용자의 의도대로 쉽게 조종할 수 있도록 해주는 인터페이스를 디자인하기가 어렵기 때문이다. 본 논문에서는 자유도(DOF)가 높은 캐릭터의 움직임을 제어하기 위해 오랫동안 인형극에서 사용되고 있는 마리오넷 조종 기법[5]을 응용한 마리오넷 시스템을 제안하고자 한다. 우리는 가상 마리오넷 시스템을 물리기반 모델링과 햅틱 인터페이스를 기반으로 구현하였고, 이 시스템을 통해 높은 자유도를 가지는 유관절체 캐릭터의 복잡한 움직임을 쉽게 생성해낼 수 있었다. 그리고 사용자에게 햅틱 포스 피드백을 줌으로써 더욱 정교한 마리오넷을 조작이 가능하도록 하였다. 이 시스템을 일반적인 유관절체에 적용한다면 다양한 움직임을 쉽고 빠르게 생성할 수 있을 것이다.

• Journal of the Korea Computer Graphics Society
• /
• v.18 no.4
• /
• pp.35-40
• /
• 2012

Simulation of deformation and fracture is one of the most important physics-based techniques in film production and real-time applications such as computer games. This paper proposes a practical approach to real-time deformation and fracturing. We adopt solid simulation with oriented particles [1] to simulate large deformation robustly, and develop a fracturing scheme to accommodate material failure when excessively stretched or compressed. The proposed method decomposes linear deformation into optimal rotation and pure stretching precisely in shape matching with oriented particles so that fracturing criteria can be easily formulated in terms of stretching. Experimental results show that the proposed method runs in real-time even for large meshes and it can simulate large deformation and fracturing.

• Proceedings of the Korea Society for Simulation Conference
• /
• 1997.04a
• /
• pp.81-85
• /
• 1997

In a virtual environment, agents must demonstrate some degree of realism and interactivity. This paper discusses the algorithm that enables agents to navigate a virtual road network realistically and interactively. The road description files written in this language provide the information of road environments to the navigating agents and the scene visualizer. We call this navigating agent in the road an ambient car. The ambient cars must follow the traffic rules as human does. To do this, the ambient car should continuously check its circumstances, such as, the traffic lights, lanes, road signs, and other ambient cars. Because of the huge scale of road network and the large number of ambient cars, the algorithm considers only the area where the participant is currently located. By this locality, the performance of the whole system does not fluctuate much in different situations. The behavior of ambient cars according to the predefined rules may appear monotonous. We added probability distribution functions to introduce some randomness. We implemented the above idea on silicon Graphics Indigo 2 workstation. The ambient car exhibited its awareness of lanes, traffic lights, and other cars. The participants could hardly distinguish between a human-controlled car and computer-controlled ambient car generated by the algorithm.

• Journal of the Korea Society of Computer and Information
• /
• v.21 no.2
• /
• pp.9-16
• /
• 2016

Recently, many research groups have focused on GPGPUs in order to improve the performance of computing systems. GPGPUs can execute general-purpose applications as well as graphics applications by using parallel GPU hardware resources. GPGPUs can process thousands of threads based on warp scheduling and CTA scheduling. In this paper, we utilize the traditional CTA scheduler to assign a various number of CTAs to SMs. According to our simulation results, increasing the number of CTAs assigned to the SM statically does not improve the performance. To solve the problem in traditional CTA scheduling schemes, we propose a new IPC-based dynamic CTA scheduling scheme. Compared to traditional CTA scheduling schemes, the proposed dynamic CTA scheduling scheme can increase the GPU performance by up to 13.1%.

• The KIPS Transactions:PartA
• /
• v.14A no.7
• /
• pp.421-434
• /
• 2007

Among many other CG generated natural scenes, the representation of ocean surfaces is one of the most complicated and time-consuming problem because of its large extent and complex surface movement. We present a hybrid method to represent and animate unbound deep-water ocean surfaces by utilizing graphics processor as both simulation and rendering core. Our technique is mainly based on spectral approaches that generate a high-detailed height field using Fourier transform on a 2D regular grid. Additionally, we incorporate Gerstner model and generate low-detailed height field on a 2D projected grid in order to represent large waves and main structure of ocean surface. There is no interruption between CPU and GPU, and no need to transfer simulation results from the system memory to graphics hardware because the entire simulation and rending processes are done on graphics processor. As a result we can synthesize and render realistic water surfaces in real-time. Proposed techniques are readily adoptable to real-time applications such as computer games that have heavy work load on CPU but still demand plausible natural scenes.

• Journal of Digital Contents Society
• /
• v.9 no.2
• /
• pp.269-276
• /
• 2008

Recently, the concerning about cultural heritages has been increased. As a result, the protection, repairing and restoration of cultural assets have been actively in progress. The biggest project of cultural asset reconstructions is the restoration of Kyungbok Palace and it has been in proceed step by step since in 1989. The actual sizes of these traditional buildings have been measured and recorded for future maintenance. In this paper, the 3D computer graphic technique is used to help understanding the inner structures of the traditional buildings as well as their construction processes. In other word, the construction simulation of Keunjeongjun which is the center building of Kyungbok Palace have been produced using 3D computer graphic techniques. The purpose of this project is aiding people in understanding the process of traditional palace architecture in Korea.

• Journal of the Korea Computer Graphics Society
• /
• v.15 no.1
• /
• pp.1-6
• /
• 2009

This paper presents a new CIP method for unstructured mesh to reduce the numerical dissipation. To reflect precise physical characteristics, CIP method updates both the physical quantity and the derivative information. The proposed method uses the Finite Volume Method(FVM) to solve the non-advection term of CIP equation. And we performed several experiments to improve the accuracy of third-order interpolation. Our result shows that our algorithm has less numerical dissipation than that of linear advection solver.

• The KIPS Transactions:PartA
• /
• v.12A no.4 s.94
• /
• pp.327-332
• /
• 2005

In the field of computer graphics, we have several research results to display the ocean waves on the screen, while we still not have a complete solution yet. Though ocean waves are constructed from a variety of sources, the dominant one is the surface gravity wave, which is generated by the gravity and the wind. In this Paper, we Present a real-time surface gravity wave simulation method, derived from a precise ocean wave model in the oceanography. There are research results based on the Pierson-Moskowitz(PM) model[1], which assumes infinite depth of water and thus shows some mismatches in the case of shallow seas. In this paper, we started from the Texel, Marsen and Arsloe(TMA) model[2], which is a more precise wave model and thus can be used to display more realistic ocean waves. We derived its implementation model for the graphics applications and our prototype implementation shows about 30 frames per second on the Intel Pentium 4 1.6GHz-based personal computer. Our major contributions to the computer graphics area ill be (1) providing more user-controllable parameters to finally generate various wave shapes and (2) the improvement on the expression power of waves even in the shallow seas.

• Journal of the Korea Computer Graphics Society
• /
• v.19 no.3
• /
• pp.1-11
• /
• 2013

Fluid Implicit Particle (FLIP) method is used in Visual Effect(VFX) industries frequently because FLIP based simulation show high performance with good visual quality. However in large-scale fluid simulations, the efficiency of FLIP method is low because it requires many particles to represent large volume of water. In this papers, we propose a novel hybrid method of simulating fluids to supplement this drawback. To improve the performance of the FLIP method by reducing the number of particles, particles are deployed inside thin layers of the inner surface of water volume only. The coupling between less-disspative solutions of FLIP method and viscosity solution of level set method is achieved by introducing a new surface reconstruction method motivated by surface reconstruction method[1] and moving least squares(MLS) method[2]. Our hybrid method can generate high quality of water simulations efficiently with various multiscale features.

• Journal of the Korea Computer Graphics Society
• /
• v.24 no.3
• /
• pp.83-92
• /
• 2018

In this paper, we propose a system to a criminal profiling simulation training and assessment with virtual reality technology. Profiling has emerged as the incidence of violent crime has increased by 45.2 % in the country over the past decade. However, the number of profilers in Korea is 36, due to the problem of existing courses. "Criminal Reproduction Learning" is the common way to profiling training, but there are numerous constraints that prevent practical training. Thus, the system used virtual reality technology to overcome existing constraints. Users can receive simulation training and assessment of profiling at crime scene that have been implemented as virtual reality, with an immersive experience through interaction. We expect this system to contribute to the activation of profiling education in many institutions and to the development of good profilers with diverse training.