• Journal of Electrical Engineering and information Science
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• v.3 no.2
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• pp.202-210
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• 1998

This paper is concerned with an efficient generation of stereoscopic views for complex virtual environments by exploiting frame coherence in visibility. The basic idea is to keep visible polygons throughout the rendering process. P-buffer, a buffer of image size, holds the id of the visible polygon for each pixel. This contrasts to the frame buffer and the Z-buffer which hold the color information and the depth information, respectively. For the generation of a consecutive image, the position and the orientation of the visible polygons in the current view are updated according to the viewer's movements, and re-rendered on the current image under the assumption that, when the viewer moves slightly, the visibility of polygons remains unchanged. In the case of stereoscopic views, it may not introduce much difficulty when we render the right(left) image using visible polygons on the (right) image only, The less difference in two images is, the easier the matching becomes in perceiving depth. Some psychophysical experiments have been conducted to support this claim. The computational complexity for generating a fight(left) image from the previous left(right) image is bounded by the size of image space, and accordingly. It is somewhat independent of the complexity of the 3-D scene.

• Journal of the Korea Computer Graphics Society
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• v.26 no.3
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• pp.123-131
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• 2020

This study proposes a real-time rendering algorithm for lighting when each of more than 100,000 moving particles exists as a light source. Two 3D textures are used to dynamically determine the range of influence of each light, and the first 3D texture has light color and the second 3D texture has light direction information. Each frame goes through two steps. The first step is to update the particle information required for 3D texture initialization and rendering based on the Compute shader. Convert the particle position to the sampling coordinates of the 3D texture, and based on this coordinate, update the colour sum of the particle lights affecting the corresponding voxels for the first 3D texture and the sum of the directional vectors from the corresponding voxels to the particle lights for the second 3D texture. The second stage operates on a general rendering pipeline. Based on the polygon world position to be rendered first, the exact sampling coordinates of the 3D texture updated in the first step are calculated. Since the sample coordinates correspond 1:1 to the size of the 3D texture and the size of the game world, use the world coordinates of the pixel as the sampling coordinates. Lighting process is carried out based on the color of the sampled pixel and the direction vector of the light. The 3D texture corresponds 1:1 to the actual game world and assumes a minimum unit of 1m, but in areas smaller than 1m, problems such as stairs caused by resolution restrictions occur. Interpolation and super sampling are performed during texture sampling to improve these problems. Measurements of the time taken to render a frame showed that 146 ms was spent on the forward lighting pipeline, 46 ms on the defered lighting pipeline when the number of particles was 262144, and 214 ms on the forward lighting pipeline and 104 ms on the deferred lighting pipeline when the number of particle lights was 1,024766.

• Journal of the HCI Society of Korea
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• v.1 no.2
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• pp.1-8
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• 2006

This paper presents a development of new haptic API (Application Programming Interface) that is called K-$Touch^{TM}$ haptic API. It is designed in order to allow users to interact with objects by kinesthetic and tactile modalities through haptic interfaces. The K-$Touch^{TM}$ API would serve two different types of users: high level programmers who need an easy to use haptic API for creating haptic applications and researchers in the haptic filed who need to experiment or develop with new devices and new algorithms while not wanting to re-write all the required code from scratch. Since the graphic hardware based kinesthetic rendering algorithm implemented in the K-$Touch^{TM}$ API is different from any other conventional kinesthetic algorithms, this API can provide users with haptic interaction for various data representations such as 2D, 2.5D depth(height field), 3D polygon, and volume data. In addition, this API supports kinesthetic and tactile interaction simultaneously in order to allow users with realistic haptic interaction. With a wide range of applicative characteristics, therefore, it is expected that the proposed K-$Touch^{TM}$ haptic API will assists to have deeper recognition of the environments, and enhance a sense of immersion in environments. Moreover, it will be useful development toolkit to investigate new devices and algorithms in the haptic research field.

• Journal of the Korea Computer Graphics Society
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• v.5 no.2
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• pp.9-23
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• 1999

Visibility preprocessing is a useful method to reduce the complexity of scenes to be processed in real-time, and so enhances the overall rendering performance for interactive visualization of virtual environments. In this paper, we propose an efficient visibility preprocessing method. In the proposed method, we assume that navigatable areas in virtual environments are partitioned into rectangular parallelpiped cells or sub-worlds. To preprocess the visibility of each polygon for a given partitioned cell, we should determine at least the area-to-area visibility. This is inherently a four-dimensional problem. We efficiently express four-dimensional visibility information on two-dimensional spaces and keep it within a ternary tree, which is conceptually similar to a BSP(Binary Space Partitioning) tree, by exploiting the characteristics of conservative visibility. The proposed method is able to efficiently handle more general environments like urban scenes, and remove invisible polygons jointly blocked by multiple occluders. The proposed method requires O(nm) time and O(n+m) space. By selecting a suitable value for m, users can select a suitable level of trade-off between the preprocessing time and the quality of the computational result.

• Journal of Korean Society for Geospatial Information Science
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• v.6 no.2 s.12
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• pp.133-141
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• 1998

Terrain modelling is composed of a method using the rectangular grid and another using the triangulated irregular network. The method using the triangulated irregular network is most widely used because it can express the characteristics of the terrain well with only a small amount of information on the terrain and also reduces the rendering time. The process of extracting the surface-specific point and a triangular process is needed to construct such triangulated irregular network. This paper concentrates on the process of extracting the surface-specific point. The 8-direction neighborhood method and other transformed methods of the former method are frequently used to extract the surface-specific point. Another method which eliminates the unnecessary points using the Polygon reduction method is also suggested However, the 8-direction neighborhood method has a big fault of also drawing out some unnecessary points. To resolve such problem, we suggest a method of extracting the surface-specific point using the cross section of the terrain. This method reduces the time to extract the surface-specific point and enables a more precise extraction with less terrain information.

• Journal of Korea Multimedia Society
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• v.11 no.9
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• pp.1245-1257
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• 2008

The establishment of a production pipeline imported 30 computer graphics is suggested in this paper to improve the efficiency of existing production pipeline of clay animation. The point is that the process of building clay characters that remains labor intensive among the existing procedures is replaced by the process of creating computer generated characters. In order to create characters out of clay by means of 30 computer graphics, a diffuse map and displacement map are made of an oil-based clay according to the UVW coordination of polygon modeling, which is the same color and kind of clay used to make a clay character. In addition, a panoramic HDRI recording system is developed to record the lighting information of shooting environment for miniature sets, which is imported in 3D computer graphic tools as digital light source. On account of the new production pipeline, a hyper realistic rendering image can be produced, and at the same time it improves the traditional pipeline of stop motion animation that is know-how based procedure of a complete artist by the engineering approach to the automatic process.

• Journal of the Korea Computer Graphics Society
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• v.13 no.1
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• pp.15-24
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• 2007

This study is focused on fellowing two issues for simulating colored paper mosaic. The first one is paper tile generation, and the other one is arrangement. At first we define the paper data as two layered polygon. Then, generate paper tile from paper data, and attach it on the best location of canvas according to energy value. The proposed method in this study has some benefits like follow. First, we can obtain more natural shaped paper tile because the phase is similar to real process of fearing paper. Second, if we redefine the structure of paper like newspaper, magazine and so on, the result can be generated with the variable type of paper. And lastly, by adjusting parameters of energy function, we can control the position of the torn paper.

• Journal of Korea Multimedia Society
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• v.10 no.10
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• pp.1310-1318
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• 2007

First of all, What was the modeling technique used to model 3D-Game character? It's a technique developed along several years, by experience... here is the bases Low polygons characters I always work in low polygon for two reasons -You can easily modify a low-poly character, change shapes, make morph for facial expressions etc -You can easily animate a low-poly character When the modeling is finished, Second, In these days, Computer hardware technologies have been bring about that expansion of various 3D digital motion pictured information and development. 3D digital techniques can be used to be diversity in Animation, Virtual-Reality, Movie, Advertisement, Game and so on. Besides, as computing power has been better and higher, the development of 3D Animations and Character are required gradually. In order to satisfy the requirement, Research about how to make 3D Game modeling that represents Character's emotions, sensibilities, is beginning to set its appearance. 3D characters in 3D Games are the core for the communications of emotion and the informations through their facial expression and characteristic motions, Sounds to Users. All concerning about 3D motion and facial expression are getting higher with extension of frequency in use. Therefore, in this study we suggest the effective method of modeling for 3D character and which are based on 2D Graphics.

• 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.