• Journal of information and communication convergence engineering
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• v.1 no.2
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• pp.82-87
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• 2003

We are able to work on the shared virtual space in Web-based Collaborative Design System using only Internet and Web browser. Then the users will share 3D objects and must be able to pick the objects effectively which they want to manipulate. In this paper, picking is implemented not only by computing intersection of mouse pointer with the objects of the virtual world, but also by using capabilities and attributes of scene graph node, by setting bounds intersection testing instead of geometric intersection testing, by limiting the scope of the pick testing, using Java 3D. These methods can reduce the computation of picking and can pick 3D objects effectively and easily using the system of hierarchy.

• Journal of the Korea Society of Computer and Information
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• v.13 no.5
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• pp.11-18
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• 2008

One of important Issues in computer graphics field is to communicate among users in virtual world like secondlife. However, in 3D virtual world, users' needs to wish to build their own contents in 3D virtual space are rising, similarly, users produce own homepage and animation, and leave writing in notice board. In this paper, we tried to achieve this by introducing semantic annotation object concept, which is a kind of annotation method in 3D virtual world. User can retrieve an 3D object by searching corresponding annotation data. This method can build semantic 3D virtual world and enable users to search 3D objects by integrating 3D object and 2D semantic multimedia information. Also, through a comparison experiment with proposal system and general 3D virtual world. the performance of proposed system is evaluated.

• Communications for Statistical Applications and Methods
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• v.11 no.2
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• pp.345-353
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• 2004

Graphical methods for the specification of the curvature as a function of two predictors are animated to see the effect of an added variable to the model. Through a 3D animated plot it might be difficult to find a sequence of interpretable plots. But examples demonstrate that useful information can be obtained by using rotation technique in 3D plot. Besides 3D plots, an example of 2D animated plot applied to the case of high correlation between predictors and an added predictor is also given. It implies that speed of the convergence to a certain image in a dynamic plot may be understood as an influence of collinearity.

• Cartoon and Animation Studies
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• s.48
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• pp.45-67
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• 2017

Many of the modern animations have 3D technology, and as time goes by, their production technology becomes more diverse and sophisticated. When John Alan Lasseter insisted on studying CG animation technology, he might have taken our jobs to the computer in the near future, as many people were worried about. It may be premature to worry that an unstable future may become a reality at this point, but I do not think there will be any difference in the fact that many animations are being produced using 3D technology. Since the Toy Story was screened in 1995, the 3D animation production technology has started to develop rapidly and now it has been elaborately developed so that it can not distinguish the part where computer graphics technology is applied from the live film. On the other hand, Disney's 2D animation part falls into the decline path because the appearance of 3D animation was perceived as a new expression technique at that time, and the efficiency of the work process was superior to the 2D animation in addition to receiving the attention from the audience. Is it necessary to accept the retrogression of 2D animation technology, reflecting the environment of the animation industry that 3D animation production technology has become mainstream in the first 20 years since the first theatrical works appeared? Since 2D animation technology has a long history and is still attractive to the audience, it is not hard to find an attempt to combine 2D and 3D animation technology. In this paper, I want to study 2D hand - drawn character in 3D animation. Through this, it is hoped that animation convergence technology will be applied more actively in the future.

• Journal of the Korea Computer Graphics Society
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• v.29 no.1
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• pp.13-22
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• 2023

In this paper, we present a method for estimating full 3D shapes from given 2D silhouette images of human bodies. Because the silhouette only consists of the partial information on the true shape, it is an ill-posed problem. To address the problem, we use the statistical human shape space obtained from the existing large 3D human shape database. The method consists of three steps. First, we extract the boundary pixels and their appropriate normal vectors from the input silhouette images. Then, we initialize the correspondences of each pixel to the vertex of the statistically-deformable 3D human model. Finally, we numerically optimize the parameters of the statistical model to fit best to the given silhouettes. The viability and the robustness of the method is demonstrated with various experiments.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1991.10a
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• pp.69-72
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• 1991

This paper proposes an efficient algorithm that constructs 3 dimensional solid object from orthographic views. The 3D object construction algorithm inputs vertices and edges information of 3 orthogonal views, generates 2 dimensional surfaces of input views, 3 dimensional possible vertices, possible edges and possible surfaces, compares 2 dimensional projections of 3 dimensional possible surface with two dimensional surfaces from orthogonal views and then determines the solution. This algorithm has been proved to be efficient in reducing the time taken and is useful for CAD system, 3 dimensional scene analysis system and object modellings for 3D graphics. The algorithm has been implemented in C language on the IBM PC/AT.

• Journal of Korea Multimedia Society
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• v.9 no.8
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• pp.1010-1019
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• 2006

CAD system is a very important technology in designing the products which we are using today. This CAD technology has been enlarging its area into 3D CAD systems with the development of computer graphics technologies. In particular, such advances have been realized in special area such as the CAD system for designing shoes. However, because it is difficult to design a 3D CAD system, most CAD developments except for major CAD software companies usually have employed the AutoCAD which realizes 3D concepts. Also, many shoes' designers have been skilled with 2D shoe CAD systems and then they can make high achievements. Therefore, we design a new shoe CAD system with advantages of 2D CAD system and 3D CAD system. We also implement the scheme to transfer the data between 2D CAD system and 3D CAD system and also grading technologies to get patterns of various shoes size from a basic shoe's design.

• Journal of the Korea Computer Graphics Society
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• v.26 no.3
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• pp.87-97
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• 2020

In this paper, we propose a novel neural relighting that infers a relighted rendering image based on the user-guided specular highlight map. The proposed network utilizes a pre-trained neural renderer as a backbone network learned from the rendered image of a 3D scene with various lighting conditions. We jointly optimize a 3D light position and its associated relighted image by back-propagation, so that the difference between the base image and the relighted image is similar to the user-guided specular highlight map. The proposed method has the advantage of being able to explicitly infer the 3D lighting position, while providing the artists' preferred 2D screen-space interface. The performance of the proposed network was measured under the conditions that can establish ground truths, and the average error rate of light position estimations is 0.11, with the normalized 3D scene size.

• Journal of the Korea Computer Graphics Society
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• v.2 no.2
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• pp.37-44
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• 1996

Networked virtual reality systems provide a consistent virtual world to the users, possibly distributed across long distances, and have been widely applied in the military, entertainment, and architectural areas. Large processing requirements, however, made these systems be mainly researched on the platforms of high-performance graphics workstations. This paper presents several problems when networked virtual reality systems are implemented on commodity PCs: two problems related with 3D graphical processing, and the other related with network bandwidth and transmission delay. We also suggest solutions to these problems and analyze their performance effect based on an architectural simulation application.

• Journal of the Korea Computer Graphics Society
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• v.20 no.2
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• pp.1-11
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• 2014

The quality of 2D-to-3D conversion depends on the accuracy of the assigned depth to scene objects. Manual depth painting for given objects is labor intensive as each frame is painted. Specifically, a human is one of the most challenging objects for a high-quality conversion, as a human body is an articulated figure and has many degrees of freedom (DOF). In addition, various styles of clothes, accessories, and hair create a very complex silhouette around the 2D human object. We propose an efficient method to estimate visually pleasing depths of a human at every frame in a monocular video. First, a 3D template model is matched to a person in a monocular video with a small number of specified user correspondences. Our pose estimation with sequential joint angular constraints reproduces a various range of human motions (i.e., spine bending) by allowing the utilization of a fully skinned 3D model with a large number of joints and DOFs. The initial depth of the 2D object in the video is assigned from the matched results, and then propagated toward areas where the depth is missing to produce a complete depth map. For the effective handling of the complex silhouettes and appearances, we introduce a partial depth propagation method based on color segmentation to ensure the detail of the results. We compared the result and depth maps painted by experienced artists. The comparison shows that our method produces viable depth maps of humans in monocular videos efficiently.