• 한국게임학회 논문지
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• 제17권1호
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• pp.7-16
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• 2017

3D 게임그래픽 표현기술은 게임콘텐츠발전과 함께 콘텐츠 분야에서 중요한 요소가 되었다. 특히 게임 캐릭터 표현 기술은 사실적인 그래픽 기술과 시각적인 즐거움을 주는 것 이외에 게임을 진행하는 게임에 대한 몰입도의 중간 단계역할을 하며 플레이어가 마치 게임 속에서 영웅적인 모험을 즐길 수 있도록 착각을 만들어 낸다. 3D 게임에 있어서 게임캐릭터의 높은 완성도는 개발과정 가운데 캐릭터 설정작업의 세심한 디테일작업과 신중함이 주요요인으로 작용한다[3]. 본 논문에서는 게임구현을 위하여 인지적 AI 알고리즘이 적용된 3D 유니티 게임 엔진을 사용하여 radiosity의 수학적인 모델과 기본적인 radiosity 모델, 점진적 개선 radiosity 모델 기법을 방법론을 소개하고, 모바일 게임에 적용한 캐릭터 표현기법을 제안하려고 한다. 게임엔진에 실제적으로 적용하여보니 렌더링과정과 모의실험에서 표면의 투영도는 게임콘텐츠 환경의 조명도에 따라 변화됨을 발견 할 수 있어서, 전체적으로 질 높은 게임캐릭터가 완성되었음이 확인 되었다.

• 한국태양에너지학회 논문집
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• 제23권3호
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• pp.93-102
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• 2003

One of the promising optical daylighting systems is light shelf type daylighting system, Two types of lighting performance analysis methods are 1) Ray-Tracing method and 2) Radiosity method. The purpose of this paper is to compare two methods in terms of advantages and disadvantages by further looking at the detail algorithm. Also. model verification with Lightscape simulations has been conducted. Effectiveness of light penetration factor in terms of daylighting factor has been investigated and quantified. In summer time. the performance of the light shelf was twice better than the case without it.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1999년도 KOBA 방송기술 워크샵 KOBA Broadcasting Technology Workshop
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• pp.15.1-21
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• 1999

Radiosity method is a global illumination model for image synthesis. It computes all energy interactions among diffuse elements in a virtual environment. One of the major drawbacks if its time consuming computation. Existing radiosity algorithms for static scene is difficult to be applicable to dynamic environments. In this paper we proposed an hierarchical scene partition scheme to speedup the link update computations in the dynamic environments. Since the proposed spatial data structure is global, it not only can be used to speedup the culling of non-affected links after geometry change, but also can be used to accelerate the subsequent visibility computation. Several empirical tests are given to show the efficiency of our improved algorithm.

• 한국산업융합학회 논문집
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• 제4권3호
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• pp.319-327
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• 2001

The objective of this study is to clarify the effect of thermal radiation environments on human thermal comfort, depending on different canyon types and surface materials on the human thermal comfort in a housing complex in Pohang city, Korea. For this purpose, the operative temperature and new effective temperature were calculated based on the modified mean radiant temperature of canyon models variated by the existence of direct radiation existence, surface materials, and the width and length of the street spaces in a housing complex. These indices for the canyon have been calculated from the meteorological data of Pohang city, which include air temperature, relative humidity, air velocity, global solar radiation and cloud. And the monthly averages of these climate factors measured at noon have been used. The results are as follows: (1) It is revealed that the short-wave radiosity reached the human body is affected by direct solar radiation and surface materials, and the long-wave radiosity by canyon types. (2) The existence of direct solar radiation, the kinds of surface materials and canyon types affect operative temperature($OT_n$) and new effective temperature($ET^*{_n}$). (3) The analysis of the human heat balance in the canyon indicates that the influence of radiation on human body is marc likely to be affected by the existence of direct solar radiation on human model.

• 한국컴퓨터그래픽스학회논문지
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• 제1권2호
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• pp.234-240
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• 1995

광선추적법에서 계산시간의 대부분은 광선과 물체와의 교차 검사에 사용된다. 그러므로 빠른 교차검사는 광선추적 알고리즘의 속도 증가를 가져올 수 있다. 따라서 본 논문에서는 광선 추적 알고리즘을 이용하여 삼각형이나 사각형등의 물체로 구성된 이미지를 생성할 때 전처리과정(preprocessing)에서 미리 계산된 두 상수 vector $\hat{u}$과 $\hat{v}$을 이용하여 지금까지 알려진 방법보다 빠른 교차 검사를 수행함으로써 속도를 향상 시키는 방법을 제안한다. 또한 이 결과를 삼각형의 보간(interpolation)에서 뿐만 아니라, 적응분할(adaptive subdivision) 방법을 사용하는 래디오시티 모델(radiosity model)에서 자주 사용되는 일반 사각형에서의 효율적인 bilinear interpolation 기법을 제시한다.

• 한국디지털건축인테리어학회논문집
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• 제5권1호
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• pp.9-16
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• 2005

In Interior design, light is the most important factor in deciding color, texture and illumination level which are the basic factors of spatial design. To apply rendering technologies on prediction of illuminating effect, it is important to understand and analyse the basic properties of the illumination models that are local illumination model and global illumination model. The illumination models in computer graphics express the factors which determine the surface color, texture and light distribution through the reflection. The purpose of this study is to propose the best way of shading algorithm in interior space provided by the computer, based on the experimental analysis that 5 shading methods are applied to the interior space. The results of this study were as followed. 1) Local illumination models that are Lambert shading, Ground shading and Phong shading are not suitable to the prediction of interior illumination effect. 2) Ray tracing that is global illumination model could be adopted to interior illumination effects. Ray tracing is a very versatile algorithm because of the large range of lighting effects it can model. 3) Neither radiality nor ray tracing offers a complete solution for simulating all interior illumination effects. 4) Radiosity excels at rendering diffuse-to-diffuse inter-reflections and ray tracing excels at rendering specular reflections. By merging both shading techniques, that offers the best of both. Using computer technologies to simulate lighting in preliminary design stage which will provide information for designers and occupants to determine the effect of using artificial light sources at each stage of their design process. Further study in illumination analysis, prediction of illumination effect, and lighting calculation is required as computer media expands.

• 대한기계학회논문집
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• 제12권3호
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• pp.551-560
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• 1988

본 연구에서는 해석하려는 시스템의 유동 및 열전달 현상의 개념도를 Fig.1 에 나타내었다. 고체 입자는 윗부분 홈으로부터 분사되어, 선택적 투과면을 통해서 입사되는 복사열을 흡수 하며, 기체는 아래 또는 위의 홈 부분으로부터 들어와서 고체 입자와의 대류열전달로 가열이 된다. 기차게 아래 홈에서부터 분사되는 경우 대류에 의해 가열된 기체가 역성층화로 인해 부력을 받게 되어, 고체 입자의 하강 속도가 감 소할 때 입자의 체류 시간의 증가에 따른 복사열의 흡수효과에 대하여 고찰하였으며 입자의 크기, 투사 복사량, 분사속도, 입자의 질량유량 등을 파라미터로 하여 이들의 변화에 따른 영향을 규명하였다. 2-방연계를 고려한 2-방정식 모델을 구성하고 고체 입자에 대하여는 Lagrangian 방법으로 기술하였으며 수치해석에 있어 유한차분법을 도 입하고 두 상간의 상호연계는 PSI-Cell 방법을 이용하였고 복사 열유속은 2-유속 모델 (two-flux model)을 도입하여 계산하였다.

• 한국태양에너지학회 논문집
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• 제31권4호
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• pp.136-141
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• 2011

The lightshelf system reduces intense illumination levels of indoor from direct sun light and reflect to lead diffused light into indoor deeply. This study aims to design acurved-lightshelf by a ray tracing method and evaluate the daylighting performance of window integrated with the curved-lightshelf by computer simulations. For this purpose, evaluation test model was designed for the experiments to validate the simulation model, and the curved-lightshelf was designed by the ray tracing method using Ecotect. After the office model was designed using 3D simulation, the average indoor illuminance, luminance and distribution of illuminance were evaluated by simulation which has a algorithm of Radiosity and Ray-Tracing method under four different cases(case1;no lightshelf, case2; Flat board, case3; tilted at $30^{\circ}$ angle, case4; the curved-lightshelf). As results, it turns out that case1 showed higher average illuminance and case4 was more uniformly distributed than case2 and case3, In addition average luminance of case1 was also lower. indicating that the curved-lightshelf would reduce the possibility of the glare, while maintaining the sufficient daylight level.