• Journal of the Korea Computer Graphics Society
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• v.4 no.2
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• pp.33-45
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• 1998

볼륨 가시화(volume visualization)는 3차원 볼륨 데이터로부터 의미 있는 가시적 정보를 추출하도록 도와주는 연구분야이다. 볼륨 렌더링(volume rendering)은 볼륨 데이터로부터 영상(image)을 얻는 기술을 말하는데, 이러한 렌더링 기법 중 물체공간(object space)에 기반한 스플래팅(splatting) 기법은 볼륨 데이터에 존재하는 응집성(coherence)의 이점을 이용할 수 있는 팔진트리(octree)나 피라미드(pyramid)와 같은 계층구조를 적용하기 쉽다. 본 논문에서는 볼륨 데이터에 팔진트리를 적용한 기존의 스플래팅 기법에 영상공간(image space)에서의 응집성의 이점을 이용하기 위한 계층구조로 4진트리(quadtree)와 범위트리(range tree)를 적용하는 새로운 스플래팅 기법을 제안한다. 이 기법은 볼륨 데이터내의 불투명한 복셀(voxel)들에 의해 가려지는 복셀들에 대한 방문을 가능한 한 피함으로써 전체적인 스플래팅의 속도를 향상시킨다. 이 기법은 잘 알려진 팔진트리, 4진트리 그리고 범위트리를 사용함으로써 그 구현이 쉽고, 추가적으로 많은 메모리를 사용하지 않으면서도 렌더링의 속도를 효율적으로 향상시킬 수 있는 기법이다.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.5_6
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• pp.360-370
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• 2004

Adaptive mesh refinement(AMR) is one of the popular computational simulation techniques used in various scientific and engineering fields. Although AMR data is organized in a hierarchical multi-resolution data structure, traditional volume visualization algorithms such as ray-casting and splatting cannot handle the form without converting it to a sophisticated data structure. In this paper, we present a hierarchical multi-resolution splatting technique using k-d trees and octrees for AMR data that is suitable for implementation on the latest consumer PC graphics hardware. We describe a graphical user interface to set transfer function and viewing / rendering parameters interactively. Experimental results obtained on a general purpose PC equipped with an nVIDIA GeForce3 card are presented to demonstrate that the proposed techniques can interactively render AMR data(over 20 frames per second). Our scheme can easily be applied to parallel rendering of time-varying AMR data.

• Journal of the Korea Computer Graphics Society
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• v.14 no.4
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• pp.27-33
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• 2008

Physics-based graphic techniques are used when simulating and rendering natural phenomena such as smoke, water and flame with computational physics. We propose novel methods which render simulated particle data fast onto 3D using tetrahedron splat. We calculate the position and the normal vector of splat by SPH(smoothed particle hydrodynamics) method then we reconstruct splat into quadrangular pyramid to reduce seam. We implement this technique for SPH fluid simulation, and animate natural flow of water successfully.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.11
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• pp.853-858
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• 2006

In this paper, we propose a practical method for hardware-accelerated rendering of the depth image-based representation(DIBR) of 3D graphic object using graphic processing unit(GPU). The proposed method overcomes the drawbacks of the conventional rendering, i.e. it is slow since it is hardly assisted by graphics hardware and surface lighting is static. Utilizing the new features of modem GPU and programmable shader support, we develop an efficient hardware-accelerating rendering algorithm of depth image-based 3D object. Surface rendering in response of varying illumination is performed inside the vertex shader while adaptive point splatting is performed inside the fragment shader. Experimental results show that the rendering speed increases considerably compared with the software-based rendering and the conventional OpenGL-based rendering method.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.106.3-106
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• 2001

Financial institutions survive on the ability to collect and react to data. Today´s financial community is bombarded by massive amounts of information from real time data-feeds, risk management systems, and other intelligent sources. The large quantities of numerical data are virtually impossible to understand quickly. Humans have the ability to understand pictures instantaneously. Thus, by converting data into pictures, and using colour, size, shape, and pattern to define relationships, individuals can rapidly process complex Information.

• The Journal of the Korea Contents Association
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• v.12 no.2
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• pp.78-85
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• 2012

This paper proposes an efficient algorithm to develop a 3D terrain tools which is essential in the development of 3D computer games. In particular, this paper proposes a cross detection technique to improve picking speed. In other words, this paper proposes a more efficient cross detection technique consisting of a ray and a parallelogram than a cross detection technique consisting of a ray and a triangle. So, we can confirm the faster picking speed. This paper uses a picking example among DirectX SDK samples to test it. In addition, this paper compares the number of function calls for cross detection using the existing techniques and the proposed technique. As a result, in this paper the proposed technique has fallen off to about a 50 percent than the existing techniques. And if it is calculated by times, in this paper the proposed technique was reduced to 1 to 2 seconds than the existing techniques. Additionally, in this paper 3D terrain tools are provide more improved algorithms for features such as texture splatting, height map control, object arrangement and realistic water effect. So, 3D terrain tools is available efficient in the development of real 3d computer games.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.10
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• pp.768-776
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• 2006

Given an unstructured point set, we use an MLS (melting least-squares) approximation to estimate the local curvatures and their derivatives at a point by means of an approximation surface Then, we compute neighbor information using a Delaunay tessellation. feature points can then be detected as zero-crossings, and connected using curvature directions. Also this approach has a fast computation time than previous methods, which based on triangle meshes. We demonstrate our method on several large point-sampled models, rendered by point-splatting, on which the feature lines are rendered with line width determined from curvatures.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.17-22
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• 2009

In this paper, we discuss two fundamental issues of hybrid scene representation: constructing and rendering. A hybrid scene consists of triangular meshes and point-set models. Consider the maturity of modeling techniques of triangular meshes, we suggest that generate a point-set model from a triangular mesh might be an easier and more economical way. We improve stratified sampling by introducing the concept of priority. Our method has the flexibility that one may easily change the importance criteria by substituting priority functions. While many works were devoted to blend rendering results of point and triangle, our work tries to render point-set models and triangular meshes as individuals. We propose a novel way to eliminate depth occlusion artifacts and to texture a point-set model. Finally, we implement our rendering algorithm with the new features of the shader model 4.0 and turns out to be easily integrated with existing rendering techniques for triangular meshes.

• Journal of Korea Game Society
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• v.10 no.1
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• pp.57-64
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• 2010

Method of making For the improved game industry, this society was permitted as an incorporated association for spearhead of game society from Ministry of Culture & Tourism on February 14, 2001 with a sense of duty and a strong will toward a powerful game country. This society has objectives of academic research and distributions on creations of game contents, technologies of game producing and developments of game cultures. We will develop the game culture and industry through an industry-academic cooperations by each expert field, and spread out academic activities for cultivation of policy, technology, education, etc of the game industry in the future.