• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.641-642
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• 2015

Unlike for other building processes, BIM for earthwork does not need a large variety of 3D model shapes; however, it requires a 3D model that can efficiently reflect the changing features of the ground shape and provide soil type-dependent workload calculation and information on equipment for optimal management. Objects for earthwork have not yet been defined because the current BIM system does not provide them. The BIM technology commonly applied in the manufacturing center uses real-object data obtained through 3D scanning to generate 3D parametric solid models. 3D scanning, which is used when there are no existing 3D models, has the advantage of being able to rapidly generate parametric solid models. In this study, A method to generate 3D models for earthwork operations using reverse engineering is suggested. 3D scanning is used to create a point cloud of a construction site and the point cloud data are used to generate a surface model, which was then converted into a parametric model with 3D objects for earthwork

• 한국전자통신학회논문지
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• 제8권8호
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• pp.1187-1193
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• 2013

본 논문은 사실적인 3D 얼굴 모델링과 얼굴 표정 생성 시스템을 제안한다. 사실적인 3D 얼굴 모델링 기법에서 개별적인 3D 얼굴 모양과 텍스쳐 맵을 만들기 위해 Generic Model Fitting 기법을 적용하였다. Generic Model Fitting에서 Deformation Function을 계산하기 위해 개별적인 얼굴과 Generic Model 사이의 대응점을 결정하였다. 그 후, Calibrated Stereo Camera로부터 캡쳐 된 영상들로부터 특징점을 3D로 복원하였다. 텍스쳐 매핑을 위해 Fitted된 Generic Model을 영상으로 Projection하였고 사전에 정의된 Triangle Mesh에서 텍스쳐를 Generic Model에 매핑 하였다. 잘못된 텍스쳐 매핑을 방지하기 위해, Modified Interpolation Function을 사용한 간단한 방법을 제안하였다. 3D 얼굴 표정을 생성하기 위해 Vector Muscle기반 알고리즘을 사용하고, 보다 사실적인 표정 생성을 위해 Deformation 과 vector muscle 기반의 턱 rotation을 적용하였다.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2007년도 학술대회 1부
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• pp.1006-1011
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• 2007

Active Appearance Models은 객체의 모델링에 널리 사용되며, 특히 얼굴 모델은 얼굴 추적, 포즈 인식, 표정 인식, 그리고 얼굴 인식에 널리 사용되고 있다. 최초의 AAM은 Shape과 Appearance가 하나의 계수에 의해서 만들어 지는 Combined AAM이였고, 이후 Shape과 Appearance의 계수가 분리된 Independent AAM과 3D를 표현할 수 있는 Combined 2D+3D AAM이 개발 되었다. 비록 Combined 2D+3D AAM이 3D를 표현 할 수 있을지라도 이들은 공통적으로 2D 영상을 사용하여 모델을 생산한다. 본 논문에서 우리는 stereo-camera based 3D face capturing device를 통해 획득한 3D 데이터를 기반으로 하는 3D AAM을 제안한다. 우리의 3D AAM은 3D정보를 이용해 모델을 생산하므로 기존의 AAM보다 정확한 3D표현이 가능하고 Alignment Algorithm으로 Inverse Compositional Image Alignment(ICIA)를 사용하여 빠르게 Model Instance를 생산할 수 있다. 우리는 3D AAM을 평가하기 위해 stereo-camera based 3D face capturing device로 촬영해 수집한 한국인 얼굴 데이터베이스[9]로 얼굴인식을 수행하였다.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.674-675
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• 2015

A 3D indoor model becomes an indiscernible component of BIM (Building Information Modeling) and GIS (Geographic Information System). However, a huge amount of time and human resources are inevitable for collecting spatial measurements and creating such a 3D indoor model. Also, a varied forms of 3D indoor models exist depending on their purpose of use. Thus, in this study, three different 3D indoor models are defined as 1) omnidirectional images, 2) a 3D realistic model, and 3) 3D indoor as-built model. A series of reconstruction methods is then introduced to construct each type of 3D indoor models: they are an omnidirectional image acquisition method, a hybrid surveying method, and a terrestrial LiDAR-based method. The reconstruction methods are applied to a large and complex atrium, and their 3D modeling results are compared and analyzed.

• 한국CDE학회논문집
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• 제8권2호
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• pp.122-132
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• 2003

STEP AP218 has a standard schema to represent the structural model of a midship section. While it helps to exchange ship structural models among heterogeneous automation systems, most shipyards and classification societies still exchange information using 2D paper drawings. We propose a feature parameter input method to generate a 3D STEP model of a ship structure from 2D drawings. We have analyzed the ship structure information contained in 2D drawings and have defined a data model to express the contents of the drawing. We also developed a QUI for the feature parameter input. To translate 2D information extracted from the drawing into a STEP AP2l8 model, we have developed a shape generation library, and generated the 3D ship model through this library. The generated 3D STEP model of a ship structure can be used to exchange information between design departments in a shipyard as well as between classification societies and shipyards.

• Journal of Computational Design and Engineering
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• 제1권2호
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• pp.96-102
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• 2014

In the field of design and manufacturing, there are many problems with managing dynamic states of three-dimensional (3D) objects. In order to solve these problems, the four-dimensional (4D) mesh model and its modeling system have been proposed. The 4D mesh model is defined as a 4D object model that is bounded by tetrahedral cells, and can represent spatio-temporal changes of a 3D object continuously. The 4D mesh model helps to solve dynamic problems of 3D models as geometric problems. However, the construction of the 4D mesh model is limited on the time-series 3D voxel data based method. This method is memory-hogging and requires much computing time. In this research, we propose a new method of constructing the 4D mesh model that derives from the 3D mesh model with continuous rigid body movement. This method is realized by making a swept shape of a 3D mesh model in the fourth dimension and its tetrahedralization. Here, the rigid body movement is a screwed movement, which is a combination of translational and rotational movement.

• 한국정보통신학회논문지
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• 제13권5호
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• pp.877-886
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• 2009

본 논문은 웹 기반 3D 패션몰을 위한 의복 시뮬레이션 시스템의 설계 기법 및 구현 방법에 대해 제한한다. 웹 3D 패션몰은 마우스 조작이 쉬운 Web3D 저작툴인 ISB로 구현하였고, 3D 인체 모델과 의상 아이템 모델은 3D MAX를 이용하여 로폴리곤 모델링으로 제작하였고, 생성된 3D 인체 모델과 의상 아이템 모델을 XML 형식으로 출력시켜 저장한 후, Direct3D를 이용하여 제작된 ActiveX 컨트롤을 사용하여 웹상에서 3D 인체 모델과 의상 아이템 모델의 정합과 애니메이션을 구현하였다. 또한 텍스타일 팔레트를 제작하여 의상 아이템 모델에 맵핑하는 과정을 알파블 렌딩 기법을 적용하여 구현하였다.

• 패션비즈니스
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• 제20권3호
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• pp.30-42
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• 2016

The objective of this study was to perform 3D solid modeling from 3D scanned surface images of cotton and silk in order to calculate the thermal heat transfer responses using numerical simulations. Continuing from the previous methodology, which provided 3D surface data for a fabric through optical measurements of the fabric microstructure, a simplified 3D solid model, containing a defined unit cell, pattern unit and fabric structure, was prepared. The loft method was used for 3D solid-model generation, and heat transfer calculations, made for the fabric, were then carried out using the 3D solid model. As a result, comprehensive protocols for 3D solid-model generation were established based on the optical measurements of real fabric samples. This method provides an effective means of using 3D information for building 3D models of actual fabrics and applying the model in numerical simulations. The developed process can be used as the basis for other analogous research areas to investigate the physical characteristics of any fabrics.

• 한국의류학회지
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• 제27권7호
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• pp.770-777
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• 2003

This paper proposes a geometrical method for generating and draping the skirt 3D models. The method constructs a 3D basic skirt model using a truncated elliptical cone and generates the various skirt 3D models by controlling the elliptical cone. The B-Spline approximates the 3D drapes which change variously according to the angles and the textiles of the skirts. The mapping sources consist of the textile textures and the skirt 2D model. The 2D models are obtained by mapping the 3D skirt models to the 2D plane. The mapping sources allow us to map the textiles to the 3D skirts. We make the real skirts for the 6 kinds of angles and textiles. and investigate the data of their drape appearances. The investigated data are applied to the virtual skirts. Appearances of the virtual skirts are similar to those of the real.

• 한국CDE학회논문집
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• 제11권6호
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• pp.429-439
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• 2006

The purpose of this study is to support the integration from current 2D drawing-based design to future 3D model-based design. In this paper, an important theme is the combination between the STEP-based 2D drawing standards (i.e., AP202) and the IFC-based 3D building model standards. To achieve the purpose, two methodologies are proposed as follows: the development of IFC extension model for the 2D shape data representation by harmonizing ISO/STEP AP202; and the development of mapping solution between IFC 2D extension model and KOSDIC by constructing the exchange scenario for 2D shape data representation. It is expected that the proposed IFC2X2 2D extension model and mapping solution will offer the basis of development of the integrated standards model in AEC industry.