• The KIPS Transactions:PartB
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• v.10B no.5
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• pp.567-574
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• 2003

Application field of third dimension graphic is becoming diversification by the fast development of hardware recently. Various theory of details technology necessary to design game such as 3D MMORPG (Massive Multi-play Online Role Flaying Game) that do with third dimension. Cyber city should be absorbed. It is the detection speed that this treatise is necessary in game engine design. 3D MMORPG game engine has much factor that influence to speed as well as rendering processing because it express huge third dimension city´s grate many building and individual fast effectively by real time. This treatise nay get concept about the collision in 3D MMORPG and detection speed elevation of game engine through improved detection method. Space division is need to process fast dynamically wide outside that is 3D MMORPG´s main detection target. 3D is constructed with tree construct individual that need collision using processing geometry dataset that is given through new graph. We may search individual that need in collision detection and improve the collision detection speed as using hierarchical bounding box that use it with detection volume. Octree that will use by division octree is used mainly to express rightly static object but this paper use limited OSP by limited space division structure to use this in dynamic environment. Limited OSP space use limited space with method that divide square to classify typically complicated 3D space´s object. Through this detection, this paper propose follow contents, first, this detection may judge collision detection at early time without doing all polygon´s collision examination. Second, this paper may improve detection efficiency of game engine through and then reduce detection time because detection time of bounding box´s collision detection.

• The KIPS Transactions:PartA
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• v.13A no.4 s.101
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• pp.371-380
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• 2006

This paper utilizing model picture of finished clothes in fashion design field various material (textile fabrics) doing Draping directly can invent new design, and do not produce direction sample or poetic theme width and confirm clothes work to simulation. Also, construct database about model and material image and embodied system that can confirm Mapping result by real time. And propose clothes simulation system to dress to 3D human body model of imagination because using several cloth pieces first by process to do so that can do simulation dressing abstracted poetic theme width to 3D model here. Proposed system creates 3D model who put clothes by physical simulation that do fetters to mass-spring model after read 3D human body model file and 2D foundation pattern file. System of this treatise examines collision between triangle that compose human body model for realistic simulation and triangle that compose clothes and achieved reaction processing. Because number of triangle to compose human body is very much, this collision examination and reaction processing need much times. To solve this problem, treatise that see could create realistic picture by method to diminish collision public prosecutor and reaction processing number, and could dress clothes to imagination human body model within water plant taking advantage of Octree space sharing techniques.

• Journal of the Korea Computer Graphics Society
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• v.14 no.1
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• pp.27-33
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• 2008

Mobile systems have relatively limited resources such as low memory, slow CPU, or low power comparing to desktop systems. In this paper, we present a new 3D mesh connectivity coding algorithm especially optimized for mobile systems(i.e., mobile phones). By using adaptive octree data structure for vertex positions, a new distance-based connectivity coding is proposed. Our algorithm uses fixed point arithmetic and minimizes dynamic memory allocation, appropriate for mobile systems. We also demonstrate test data to show the utility of our mobile 3D mesh codec.

• Journal of Broadcast Engineering
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• v.14 no.4
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• pp.397-408
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• 2009

In this paper, we present a non-static color histogram method to retrieve clothing images that are similar to a query clothing. Given clothing area, our method automatically extracts major colors by using the octree-based quantization approach[16]. Then, a color palette that is composed of the major colors is generated. The feature of each clothing, which can be either a query or a database clothing image, is represented as a color histogram based on its color palette. We define the match color bins between two possibly different color palettes, and unify the color palettes by merging or deleting some color bins if necessary. The similarity between two histograms is measured by using the weighted Euclidean distance between the match color bins, where the weight is derived from the frequency of each bin. We compare our method with previous histogram matching methods through experiments. Compared to HSV cumulative histogram-based approach, our method improves the retrieval precision by 13.7 % with less number of color bins.

• Journal of the Korea Computer Graphics Society
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• v.19 no.2
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• pp.19-27
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• 2013

This paper presents a real-time GPU (Graphics Processing Unit) isosurface ray-caster that improves the performance by 4-7 folds from our previous method, while keeping the superior visual quality. Such an improvement is achieved by incorporating an efficient empty-space skipping scheme and an analytic normal computation. The empty-space skipping scheme is done by building an min/max octree computed from the BB(Bernslein-B$\acute{e}$zier)-form of spline pieces and the analytic normal Formula provides not only a nice visual quality but also an improved evaluation performance.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.11a
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• pp.1399-1402
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• 2005

본 논문은 여러 옷감 조각들을 이용하여 가상의 3차원 인체 모델에 옷을 입히기 위한 의복 시뮬레이션 시스템을 제안한다. 본 논문에서 의상 제작 과정에 사용한 방법은 2차원 옷감 조각을 디자인하는 과정과 옷감 조각을 재봉하고 여기에 제약점을 정하여 3차원 인체 모델에 의상을 입히는 과정으로 구성된다. 제안된 시스템은 3차원 인체 모델 파일과 2차원 재단 패턴 파일을 읽어 들인 다음 질량-스프링 모델에 기반한 물리적 시뮬레이션에 의해 의복을 착용한 3D 모델을 생성한다. 본 논문의 시스템은 사실적인 시뮬레이션을 위하여 인체 모델을 구성하는 삼각형과 의복을 구성하는 삼각형 사이의 충돌을 검사하고 반응 처리를 수행하였다. 인체를 구성하는 삼각형의 수가 매우 많으므로, 이러한 충돌 검사 및 반응 처리는 많은 시간을 필요로 한다. 이 문제를 해결하기 위하여, 본 논문에서는 Octree 공간 분할 기법을 이용하여 충돌 검사 및 반응 처리 수를 줄이는 방법을 이용하여 사실적인 영상을 생성할 수 있었고, 수초 이내에 가상 인체 모델에 의복을 입힐 수 있었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10a
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• pp.615-618
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• 2001

본 논문은 기존의 3D 게임 엔진에 실시간으로 상호 작용이 가능하고 3D MMORPG(Massive Multi-play Online Role flaying Game) 게임에 적합한 가상 공간을 표현하기 위한 필요한 기술을 분석하고 이를 활용하려 한다. 기존의 머드 게임에 3 차원 기술을 적용하고, 3 차원 물체를 모델링 하는데 있어서 메쉬나 버텍스, 혹은 폴리곤으로 사실적인 지형 처리와 렌드링 속도 향상을 위하여 3 차원 개체의 폴리곤을 동적으로 생성시키고 가시성 판단이나 충돌 검출을 위한 방법으로 Height field 처리 기법과 거리에 변화에 따라 다르게 모델링 된 데이터를 선택적으로 사용하는 CLOD(Continuous Level of Detail) 처리 기법과 입체 컬링 방법으로 옥트리를 이용하여 가상공간을 분해하기 위한 자료 구조로 사용한다. 거리의 변화에 따라 지형을 표현하는 vertex 들을 병합 또는 삭제함으로써 그 표현의 정도를 동적으로 달리 할 수 있는 CLOD 를 이용하여 카메라의 위치와 방향에 따라 적절한 폴리곤을 생성해 낼 수 있다. 본 논문은 기존의 3 차원 공간을 표현하기 위하여 사용되고 있는 옥트리 구조를 이용하여 공간을 분할하고, 이를 세부 수준으로 나누어 처리하기 위한 LOD(Level of Detail)와 CLOD 개념을 이용하여 외부지형을 폴리곤으로 표현하는 방법에 대한 처리 기법과 가시성 판단이나 충돌 검출을 위한 방법을 제시하려 한다.

• Journal of Korea Multimedia Society
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• v.24 no.11
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• pp.1538-1551
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• 2021

The current drone flight plan creation creates a flight path point of two-dimensional coordinates on the map and sets an arbitrary altitude value considering the altitude of the terrain and the possible flight altitude. If the created flight path is a simple terrain such as a mountain or field, or if the user is familiar with the terrain, setting the flight altitude will not be difficult. However, for drone flight in a city where buildings are dense, a safer and more precise flight path generation method is needed. In this study, using high-precision spatial information, we construct a drone safety flight map with a 3D grid map structure and propose a flight path search algorithm based on it. The safety of the flight path is checked through the virtual drone flight simulation extracted by searching for the flight path based on the 3D grid map created by setting weights on the properties of obstacles and terrain such as buildings.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.4
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• pp.235-242
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• 2022

As ship condition inspection technology has been developed, research on collecting, analyzing, and diagnosing condition information has become active. In ships, related research has been conducted, such as analyzing, detecting, and classifying major hull failures such as cracks and corrosion using 2D and 3D data information. However, for geometric deformation such as indents and bulges, 2D data has limitations in detection, so 3D data is needed to utilize spatial feature information. In this study, we aim to detect hull structural deformation positions. It builds a specimen based on actual hull structure deformation and acquires a point cloud from a model scanned with a 3D scanner. In the obtained point cloud, deformation(outliers) is found with a combination of RANSAC algorithms that find the best matching model in the Octree data structure and dataset.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.3D
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• pp.259-267
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• 2012

The development of construction automation systems is proposed as a potent solution to the difficulties encountered by the construction industry and the preparation for the rapidly changing construction environment. A research concerning an intelligent excavation system has taken place since 2006. The intelligent excavation system has several functions for environment sensing, 3D site modeling, work planning, work path generation, unmaned control, and information management. This paper presents a space information model and a work path simulator for work planning and work path generation which is one of key technologies required to apply the earthwork system to the real world. A data structure for an earthwork site is suggested. It overcomes the limitations of previous data structures such as Quadtree and Octree. The work path simulator can generate an effective work path with considering information on work environment, equipment and operator's heuristic. The work path generated by the simulator is compared with that suggested by human operators.