• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.1137-1142
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• 2006

3D 가상공간을 협업에 효과적으로 이용하기 위해서는 3D 가상공간에서 빠르고 쉽게 의사를 표현할 수 있는 기술이 필요하다. 본 연구에서는 이런 효과적인 의사표현 방법으로 Sketch 기법을 제안한다. Sketch 기법은 간단한 2D 선들의 표현을 통해 매우 빠르게 아이디어를 표현 할 수 있으며, 의도에 따라 부분을 강조하거나 가감할 수 있기 때문에 좀 더 직관적으로 의도를 전달 할 수 있다. 그래서 이러한 Sketch 를 공간상에서 손쉽게 3D 모델의 표면이나 공간 위에 입력하고, 입력한 Sketch 를 3D 가상공간과 연동하여 보여 줌으로써 쉽게 3D 가상공간 안에 Sketch 로 의견을 표현 할 수 있게 하는 Sketch 기반 인터페이스를 연구 하였다. Sketch 기법을 3D 가상공간에 적용하기 위해서는 3D 가상공간 상에서 2D Sketch 를 입력하기 위한 방법과 입력 시 발생할 수 있는 위상차의 문제를 해결해야 한다. 이 연구에서는 2D Sketch 입력을 대상 3D 객체 중심에서 Sketch할 부분의 Sketch plain 을 선택 및 생성함으로써 입력하는 방법을 연구하였으며, 입력 시 발생하는 위상차는 View-point 및 View-Plain 의 이동 등을 통해 해결점을 찾고자 하였다. 그리고 추후 연구를 통해 Sketch 를 Annotation 으로 활용, 협업에서 필요로 하는 Sketch Annotation 으로 개발하고자 한다.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.6
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• pp.450-453
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• 2009

The sketch technique is being researched as the method of expressing intentions in 3D virtual space for cooperative work. The annotation which is necessary in 3D virtual space 1) not only enables the quick, easy and intuitive delivery of contents" but 2) must enable the input of sketch even on diverse and complicated surfaces and 3) must be expressed to recognize this in various angles in case of having the significance of 3D. Even if the sketch technique settles the precondition of 1), if 2) and 3) are not considered, the annotation is unable to deliver the contents accurately to the participant of cooperative work. Accordingly, a sketch annotation technique which enables the input of annotation even on complicated surfaces and also considers the contents of 3D is proposed using sketch-box technique.

• Journal of the Korean Society of Clothing and Textiles
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• v.44 no.2
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• pp.193-208
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• 2020

This study investigated similarities and differences between 2D flat sketch, 3D virtual clothing and real clothing images. Flat sketch, 3D virtual clothing, and real clothing images of T-shirts and dresses were made. Questionnaires were prepared for fit evaluation, sensory evaluation, and location evaluation. A survey of 440 questionnaires was collected from Chinese women in their 20s and 30s. As results of the sensibility evaluation, 3D virtual clothing expressed real clothing images slightly more similar than a 2D flat sketch. As results of the fit evaluation of the dresses, 2D flat sketch and 3D virtual clothing were rated as slightly longer/wider, and real clothing images were rated as slightly shorter/narrower. The results suggested that presenting 3D images with avatars as 3D virtual clothing images will provide more accurate fit evaluation results. This study presented possibilities and methods for apparel companies to utilize 3D system as an effective apparel production tool.

• Proceedings of the Korea Society of Design Studies Conference
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• 2005.05a
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• pp.240-241
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• 2005

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.248-254
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• 2001

This paper presents a progressive algorithm for reconstructing a 3D structure from a given 2D sketch drawing (edge-vertex graph without hidden line removal) according to the user's sketch order. While previous methods reconstruct a 3D structure at once, the proposed method progressively calculate a 3D structure by optimizing the coordinates of vertices of an object according to the sketch order. The progressive method reconstructs the most plausible 3D object quickly by applying 3D constraints that are derived from the relationship between the object and the sketch drawing in the optimization process. The progressive reconstruction algorithm is discussed, and examples from a working implementation are given.

• Journal of Internet Computing and Services
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• v.21 no.1
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• pp.33-43
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• 2020

Retrieving a 3D model from a 3D database and augmenting the retrieved model in the Augmented Reality system simultaneously became an issue in developing the plausible AR environments in a convenient fashion. It is considered that the sketch-based 3D object retrieval is an intuitive way for searching 3D objects based on human-drawn sketches as query. In this paper, we propose a novel deep learning based approach of retrieving a sketch-based 3D object as for an Augmented Reality Model. For this work, we introduce a new method which uses Sketch CNN, Wasserstein CNN and Wasserstein center loss for retrieving a sketch-based 3D object. Especially, Wasserstein center loss is used for learning the center of each object category and reducing the Wasserstein distance between center and features of the same category. The proposed 3D object retrieval and augmentation consist of three major steps as follows. Firstly, Wasserstein CNN extracts 2D images taken from various directions of 3D object using CNN, and extracts features of 3D data by computing the Wasserstein barycenters of features of each image. Secondly, the features of the sketch are extracted using a separate Sketch CNN. Finally, we adopt sketch-based object matching method to localize the natural marker of the images to register a 3D virtual object in AR system. Using the detected marker, the retrieved 3D virtual object is augmented in AR system automatically. By the experiments, we prove that the proposed method is efficiency for retrieving and augmenting objects.

• Journal of Korea Multimedia Society
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• v.25 no.11
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• pp.1634-1642
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• 2022

Numerous studies have attempted to present converting 2D drawings to 3D. However, converting 3D shapes to exactly how a person thinks is challenging because 2D drawings include numerous variables and possibilities. This study focuses on visualizing 2D to 3D in a commonly used 3D animation software required in animation education or the 3D industry. We implemented our SketchTo3D tool to add the editing and automatic texture assigning method from the imported 2D image into the 3D software that previously had to be done manually. As a result, the SketchTo3D tool saves time to immediately visualize the composition, shape, and volume to express the 3D character, providing an opportunity to break down the barrier between 2D and 3D.

• International Journal of CAD/CAM
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• v.7 no.1
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• pp.113-120
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• 2007

Sketch based query plays an important role in shape matching for 3D shape retrieval system. Some researchers suggest the sketch based query interfaces. It is more effective to capture the needs of users rather than query by example. In this paper, we propose a new 2D sketch based query interface with coarse filters for shape matching. Coarse filtering enables to eliminate unfavorable shapes from shapes in DB. For the purpose of coarse filtering, we use two filters with the topological and geometric patterns. For the validity of our method, we show the experimental results.

• Journal of Internet Computing and Services
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• v.19 no.6
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• pp.91-99
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• 2018

Sketch-based 3D object retrieval is a convenient way to search for various 3D data using human-drawn sketches as query. In this paper, we propose a new method of using Sketch CNN, Wasserstein CNN and Wasserstein center loss for sketch-based 3D object search. Specifically, Wasserstein center loss is a method of learning the center of each object category and reducing the Wasserstein distance between center and features of the same category. To do this, the proposed 3D object retrieval is performed as follows. Firstly, Wasserstein CNN extracts 2D images taken from various directions of 3D object using CNN, and extracts features of 3D data by computing the Wasserstein barycenters of features of each image. Secondly, the features of the sketch are extracted using a separate Sketch CNN. Finally, we learn the features of the extracted 3D object and the features of the sketch using the proposed Wasserstein center loss. In order to demonstrate the superiority of the proposed method, we evaluated two sets of benchmark data sets, SHREC 13 and SHREC 14, and the proposed method shows better performance in all conventional metrics compared to the state of the art methods.

• Korean Journal of Computational Design and Engineering
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• v.13 no.4
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• pp.255-264
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• 2008

Research that reconstructs a 3D model from a freehand 2D sketch has gained attention since 1990s, when data integration in the CAD/CAPP/CAM/CNC chain was an important issue. However, 2D sketches in the conceptual design phase have not been integrated with the downstream CAD/CAPP/CAM/CNC chain. In this paper, we present a method to interface a freehand sketch modeling to commercial CAD systems by mapping a sketch modeling history to the macro parametric history. We use an extended ISO10303-112 standard to represent the modeling history in a gestural modeling system and translate sketch files to neutral macro files. Macro parametric translators are used to translate netural macro files to commercial CAD files.