• Journal of the Korea Computer Graphics Society
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• v.24 no.4
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• pp.11-20
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• 2018

Applications about systems integration of sensors and virtual environments have been developed increasingly. Accordingly, there is a need for the ability to represent, control, and manage physical sensors directly in a 3D virtual environment. In this research, a method of representing physical sensor devices in a 3D virtual environment has been defined using mixed and augmented reality, including virtual and real worlds, where sensors and virtual objects co-exist. The research is intended to control and manage various physical sensors through data sharing and interchange between heterogeneous computing environments. In order to achieve this, general sensor types have been classified, and a sensor based 3D scene graph for representing the functions of sensors has been defined. In addition, a sensor data model has been defined using the scene graph. Finally, a sensor 3D viewer has been implemented based on the scene graph and the data model so as to simulate the functions of sensors in indoor and outdoor 3D environments.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.1
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• pp.140-153
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• 2019

Cloase-range image information from drones and ground-based camera has been frequently used in the field of disaster mitigation with 3D modeling and mapping. In addition, the utilization of virtual reality(VR) is being increased by implementing realistic 3D models with the VR technology simulating disaster circumstances in large scale. In this paper, we created a VR training program by extracting realistic 3D models from close-range images from unmanned aircraft and digital camera on hand and observed several issues occurring during the implementation and the effectiveness in the case of a VR application in training for disaster mitigation. First of all, we built up a scenario of disaster and created 3D models after image processing with the close-range imagery. The 3D models were imported into Unity, a software for creation of augmented/virtual reality, as a background for android-based mobile phones and VR environment was created with C#-based script language. The generated virtual reality includes a scenario in which the trainer moves to a safe place along the evacuation route in the event of a disaster, and it was considered that the successful training can be obtained with virtual reality. In addition, the training through the virtual reality has advantages relative to actual evacuation training in terms of cost, space and time efficiencies.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2003.04a
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• pp.328-333
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• 2003

GIS기술은 실세계의 분석에서부터 3D 가상도시의 구축까지 매우 빠르게 발전하고 있다. 3D가상도시는 GIS 기술, 컴퓨터그래픽스 기술, 가상현실 기술, 데이터베이스 기술에 의해 컴퓨터 속에 구현이 되는 도시를 말한다. 본 연구에서는 1/1,000 수치지도를 이용하여 3D건물모델을 형성하였고, 건물모델을 형성할 때는 삼각형 메쉬를 형성하고 최적의 메쉬를 형성하기 위하여 Divide and Conquer 알고리즘을 사용하였다. 메쉬가 형성된 수치지도의 건물모델에 대하여 기존의 기하파이프라인을 개선함으로서 건물모델을 빠르게 렌더링할 수 있도록 하였다. 건물측면에 대하여는 디지틀 카메라를 이용하여 측면에 대한 이미지를 취득하고 2D Projective Transformation을 적용하여 이미지를 조정하였다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2006.05a
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• pp.143-147
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• 2006

컴퓨터 기술이 발달되면서, 3D 가상현실을 구현할 수 있는 여러 가지 도구들이 웹이나 개인용 컴퓨터에서 운용되고 있다. 또한 3D 가상현실 기술은 새로운 컴퓨터 응용분야로 전자상거래, 기업홍보, 교육, 의료, 시뮬레이션, 그리고 컴퓨터 게임까지 널리 활용되고 있다. 하지만 설계자들이 3D 모델링을 하기 위해서는 많은 시간과 노력이 요구된다. 따라서 새로운 3D 모델을 개발하는 대신에 기존의 모델을 효과적으로 재사용할 수 있다면 많은 노력과 시간을 절약 할 수 있을 것이다. 하지만 이러한 것이 가능하려면 사용자에 의해 정의된 3D 객체를 데이터베이스로부터 관련성이나 유사성이 높은 객체를 찾을 수 있어야한다. 이 논문에서는 에이전트 기법을 사용하여 메타데이터와 온톨로지 정보를 참고하여 3D 모델을 추천하는 시스템을 설계 및 구현 하였다.

• Journal of the Korea Computer Graphics Society
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• v.3 no.1
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• pp.29-36
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• 1997

Most Virtual Reality Systems have been developed to support only a single user on a stand-alone system. With increasing availability of Internet, many people are taking strong interests in distributed Virtual Reality : the virtual environment is shared by many paticipants interacting over the network. To support sharing virtual environment and interactions on a network, we developed novel contributions to 3D world description and a network model. Interactive 3D world description is based on VRML, which is extended to support multi-user interactions. Then network model in our system consists of an architecture and a set of protocols for realizing a multi-user interactive shared 3D environment in IP multicast environment.

• The Journal of Korean Institute for Practical Engineering Education
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• v.4 no.1
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• pp.72-79
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• 2012

Recently, the growth of the computer-related industries lead to the growth of the computer-aided education. Virtual training (VT) is one of the most interesting education methods. Many 3D models for the VT contents have been produced, but little research has been performed for the unified management system to promote the reuse of 3D models. This paper proposes the unified 3D model management system. The 3D model file formats are surveyed to find a format that can be easily used by many VT content production softwares. The 3D model files will be stored in a central DB server. The structure of the DB system will be designed for 3D models. The system provides an easy way to search and download a 3D model. With the proposed system, the reuse of 3D models is expected to be promoted.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.10
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• pp.521-528
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• 2007

This paper proposes a new method for the high- speed penetration detection between the 3D human body model and the 3D cloth model using a virtual cylinder, and for the correction of the 3D cloth model. Penetration sometimes occurs locally, when the cloth model is adopted geometrically to the body. This method establishes the virtual cylinder surrounding the body model and the cloth model, and selects at a time the candidates of the penetrated points using the virtual cylinder. Finally, the penetrated points are detected among the candidates. Shift of the vertices or division of the edges in the penetrated points can correct the cloth model geometrically. This method works faster than the physical-based method. The latter requires the repeated detection of the penetrated points using bounding volume and the repeated corrections of the cloth model using dynamics.

• The KIPS Transactions:PartB
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• v.9B no.2
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• pp.255-262
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• 2002

The Virtual Reality (VR) is an appealing subject which can be applied to various areas because of its merit - removal of time limits and space. Recently, as the technology of xDSL spreads widely, a concern of VR is on the on-line service of 3D model data in real time. But, the immensity of 3D model is an obstacle to achieve these endeavors. To solve these problems, the image based VR technique is applied. The proposed method in this paper is one of solutions on the immensity problem of 3D model data in the on-line services. This paper exploits the mixed technique of image based VR and surface rendering based on volume rendering. By using the proposed method, we can solve the immensity problem. Consequently, tole service user can explore virtual 2D volume model with almost equal to reality of 3D volume model. Furthermore, this paper explains a method to implement this service on general web environments. Of course, to fulfill these procedures, additional skills which reduce consuming time in data mining are also mentioned. The contribution of this paper is to provide a practical method for handling of large volume data web service in real-time. illustrative examples are presented to show the effectiveness of the proposed method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.585-590
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• 2019

The purpose of this study is to summarize the changes in virtual reality utilization in model houses through the time-by-year example of model houses and to study the use and future development of virtual reality technologies in model houses. As a result of compiling and analyzing characteristics of virtual reality utilization flow in model houses of apartments, it is as follows. First, the market for apartment model houses using virtual reality was gradually expanded for the purpose of brand promotion by private construction companies. Second, technologies that utilize virtual reality in apartment sales are changing from virtual space construction to virtual content implementation. Third, it is changing from the existing method of face-to-face and method of accessing actual promotional media to the form of publicizing apartments using virtual reality. Through this research, it is estimated that it will be used as an information medium and a form of experience using physical environment and virtual reality in a physical model house for consumers looking for model houses. This study presents the future direction of the model house, and develops it as a post-sale maintenance / management system through ICT technology (3D scanning, 3D modeling, virtual content) Further research on the technology is expected to be needed.

• The Journal of Korean Institute of Next Generation Computing
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• v.15 no.4
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• pp.40-50
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• 2019

In recent years, it is important to visualize an accurate human body model for the low-end system in the medical imaging field where augmented reality technology and virtual reality technology are used. Decreasing the geometry of a model causes a difference from the original shape and considers the difference as an error. So, the error should be minimized while reducing geometry. In this study, the organ areas of a human body in the tomographic images such as CT or MRI is segmented and 3D geometric model is generated, thereby implementing the reconstruction method of multiple resolution level-of-detail model. In the experiment, a virtual reality platform was constructed to verify the shape of the reconstructed model, targeting the spine area. The 3D human body model and patient information can be verified using the virtual reality platform.