• Journal of the Korea Computer Graphics Society
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• v.1 no.2
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• pp.226-233
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• 1995

본 논문에서는 심장과 심장 상부의 대동맥 및 폐동맥에 대한 형태-기반 보간법을 이용한 3차원 가시화 방법을 제안하였다. CT, MR과 같은 의학 영상들은 x나 y축 방향보다 z축 방향으로 더 낮은 해상도를 갖기 때문에 3차원적 가시화를 위해서는 먼저 각 단층 영상들간의 보간이 수행되어야 한다. 그러나, 지금까지 대부분의 3차원 의학영상 가시화에서는 선형보간법이나 또는 그와 유사한 보간법들을 주로 사용했는데, 이런 보간법들은 분기나 휘어지는 구조를 갖는 기관에는 좋은 결과를 생성하지 못했었다. 따라서, 본 논문에서는 분기와 휘어짐이 있는 심장부위 구조를 3차원적으로 가시화하기 위하여 형태-기반 보간법을 이용하였다. 형태-기반 보간법을 이용한 가시화는 다른 보간법을 사용한 경우와 달리 분명하고 자연스러운 구조 표현을 할 수 있었고, 각 단층 영상간의 보간수를 증가시킴에 따라 더 좋은 결과를 생성하는 것으로 나타났다.

• Journal of the Korea Computer Graphics Society
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• v.13 no.4
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• pp.1-6
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• 2007

In this paper we describe the method of controlling the animation of 3D characters according to ISO/IEC 19774 (H-Anim) specification, which has been released by Wed3D Consortium and ISO/IEC SC24 WG6. The animation structure of the H-Anim character can be defined and modified in our H-Anim editor program. Our H-Anim animator generates the character's motion automatically according to the input of motion parameters at the character's joints interactively. This paper is focused on the development of a motion generation tool for human-like characters defined by H-Anim structures.

• The Transactions of the Korea Information Processing Society
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• v.2 no.3
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• pp.390-396
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• 1995

One of the advantages of computer graphics is that it enables to view an object on different viewpoints and different angles. Therefore, a computer graphics system should be able to rotate an arbitrary object by an arbitrary angle about an arbitrary axis. This is usually done by rotating vertices that represent an object and connecting them. Hence an image may have many vertices, it is important to be able to rotate each of them quickly. Therefore, this paper is interested in a rotation matrix computation method that consists of the smallest number of computational steps. This pater proposes an algorithm that computes rotation matrix to rotate a 3 dimensional image about an arbitrary axis quickly.

• Journal of the Korea Computer Graphics Society
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• v.28 no.3
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• pp.31-43
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• 2022

Recently, metaverse is rapidly expanding its area as a platform that can be applied to various fields. In particular, the function that allows many users to interact in a three-dimensional space allows VR/AR-based educational content to be used as a more advanced concept. Due to the nature of engineering education, it is often based on three-dimensional objects. In the case of a three-dimensional object, it is difficult to explain through two-dimensional videos or documents, and it becomes more difficult to express when the process of changing the object is included. The three-dimensional space of the metaverse can improve this difficulty based on real-time rendering. Another characteristic of engineering education is that there are many invisible elements. Although it is involved in the movement of objects due to electromagnetic fields, magnetic fields, and forces, it is the main reason for increasing learning difficulty because it is invisible. These problems can also help learning because they can be visually represented in the metaverse space. In this paper, the results of the establishment of the metaverse platform for engineering education and the real-time lecture contents produced based on it are described, and the applied results and lecture evaluation are discussed. Lectures using a total of 9 metaverse contents were conducted, and 90% of the positive lecture evaluation results were obtained.

• Journal of Biomedical Engineering Research
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• v.15 no.2
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• pp.201-208
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• 1994

Many three-dimensional object modeling and display methods for computer graphics and computer vision have been developed. Recently, with the help of medical imaging devices such as computerized tomography, magnetic resonance image, etc., some of those object modeling and display methods have been widely used for capturing the shape, structure and other properties of real objects in many medical applications. In this paper, we propose the reconstruction and display method of the three-dimensional object from a series of the cross sectonal image. It is implemented by using the automatic threshold selection method and the contour following algorithm. The combination of curvature and distance, we select feature points. Those feature points are the candidates for the tiling method. As a results, it is proven that this proposed method is very effective and useful in the comprehension of the object's structure. Without the technician's responce, it can be automated.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.1
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• pp.54-59
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• 2019

The parametrization of the surface plays an important role in the 3D computer graphics and computer vision. Especially, it is essential in 3D mesh editing that manipulates the position of 3D objects on a computer monitor. Because computer monitors are two-dimensional, while vertices of objects that actually want to change are in a three-dimensional virtual space. In this study, we propose a new type of parametrization method that takes advantage of the special properties of circles that are common to local parameterization. Experimental results show that our parameterization method is more efficient in terms of time and space than the standard parameterization method that was designed by Floater et al.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.11
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• pp.2107-2115
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• 2007

In this paper, the scan conversion processor which converts the triangle represented by three vertices into pixel-level screen coordinates, depth coordinate, and color data is designed. The processor adopts scan-line algorithm which decomposes triangle into horizontal spans and then transforms the span into pixel data. By supporting top-left filling convention, it ensures that triangles that share an edge do not produce any dropouts or overlaps between adjacent polygons. It consists of about 21,400 gates and its maximum operating frequency is about 80 Mhz under 0.35um CMOS technology. Because its maximum pixel rate is about 80 Mpixels/sec, it can be applicable to mobile graphics application.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.627-630
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• 2005

This paper describes the development of a racing game with three-dimensional computer graphics as one of web-based game contents. Client user using web can access and run java applet program with download of Java Bytecode with the independence of hardware system. It consists of graphic user interface module, initial space generation module, event handler module, and thread control module. It uses 2-D linked list data structure for the 3-D graphic objects that are located in three-dimensional space for high-speed object searching and sorting. It enhances the dynamic object moving and viewing in three-dimensional space. We can use the developed racing game to inform game users of information for an advertisement like tourism information, and can apply the proposed 3-D drawing technology to 3-D game graphic engine core.

• Journal of the Korea Computer Graphics Society
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• v.21 no.2
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• pp.11-20
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• 2015

We present a new interactive technique for directing the motion sequences of an animated character by dragging its specific body part to a desired location in the three-dimensional virtual environment via a hand motion tracking device. The motion sequences of our character is synthesized by reordering subsequences of captured motion data based on a well-known graph representation. For each new input location, our system samples the space of possible future states by unrolling the graph into a spatial search tree, and retrieves one of the states at which the dragged body part of the character gets closer to the input location. We minimize the difference between each pair of successively retrieved states, so that the user is able to anticipate which states will be found by varying the input location, and resultantly, to quickly reach the desired states. The usefulness of our method is demonstrated through experiments with breakdance, boxing, and basketball motion data.

• The Journal of the Korea Contents Association
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• v.5 no.5
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• pp.115-123
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• 2005

Game industry will be one of the fastest developed industries in the 21st century. It is the outcome derived from the development of hardware such as the accumulated technology and computer in the 20th century. The development of computer graphics and hardware technique has let games have more realistic expression. The reality shown in games has influences over the movement of 3-dimensional game character as well as its background. The animation of character has been influenced by animator's level of skill, but it was problematic to have unnatural movement and long-term production time. In this regard, this study will compare the most widely used animation techniques such as Key-Frame method and Motion-Capture method each other and try to figure out which one is the most appropriate and effective method in 3 dimensional game character animation.