• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.3
• /
• pp.547-554
• /
• 2008

In this paper, two-stage pipelined floating-point multiplier (FP-MUL) is designed. The FP-MUL processor supports single precision multiplication for 3D graphic APIs, such as OpenGL and Direct3D and has area-efficient and low-latency architecture via saturated arithmetic, area-efficient sticky-bit generator, and flagged prefix adder. The FP-MUL has about 4-ns delay time under $0.13{\mu}m$ CMOS standard cell library and consists of about 7,500 gates. Because its maximum performance is about 250 MFLOPS, it can be applicable to mobile 3D graphics application.

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

• Journal of the Korea Computer Graphics Society
• /
• v.8 no.4
• /
• pp.1-7
• /
• 2002

This paper presents a new approach for modeling human limbs shape from 3D scan data. Based on the cylindrical structure of limbs, the overall shape is approximated with a set of ellipsoids through ellipsoid fitting and interpolation of fit-ellipsoids. Then, the smooth domain surface representing the coarse shape is generated as the envelope surface of ellipsoidal sweep, and the fine details are reconstructed by constructing parametric displacement function on the domain surface. For fast calculation, the envelope surface is approximated with ellipse sweep surface, and points on the reconstructed surface are mapped onto the corresponding ellipsoid. We demonstrate the effectiveness of our approach for skeleton-driven body deformation.

• Journal of the Korea Computer Graphics Society
• /
• v.11 no.1
• /
• pp.1-7
• /
• 2005

본 논문에서는 3D 게임이나 가상현실, 인터렉티브 아트 등의 실시간 환경의 컨텐츠 제작에 활용가능한 수묵담채화풍의 렌더링 기법을 제안한다. 제안된 기법은 기존의 3차원 수묵화 렌더링 연구에서는 다루지 않았던, 색채표현법과 그 합성법을 중심으로 연구되었다. 색채표현법의 경우, 일반적으로 삼색을 단계적으로 겹쳐서 표현하는 수묵담채화의 특성에 따라, 실제 그림을 그릴 때에 적용되는 삼색의 혼합방법과 순서가 자동으로 적용될 수 있는 삼색기반 구조를 통해 농담과 질감효과를 표현했으며, 또한 이러한 삼색레이어의 합성을 위해서는 안료의 광학적 성질을 반영하여 실제 회화매체에 가까운 색상을 재현할 수 있는 Kubelka-Munk(KM)모델을 적용한다. 기존의 KM모델은 비사실적 렌더링 연구 분야에서 수채화, 유화 등 서양화를 대상으로 한 색채 합성에 적용되어 왔기 때문에 기존의 연구에서 제시한 방법만으로는 삼색레이어가 겹쳐질 때 나타나는 수묵담채화의 특징과 천연 재료를 사용하는 동양 안료의 색상을 정확히 반영할 수 없었다. 따라서 본 논문에서는 실제 수묵담채화에 이용되는 전통안료의 색상 분석을 통해 KM모델에 적용할 파라미터들을 추출하고, 앞에서 설계한 삼색 기반 구조에 따라 색상을 합성하는 방법을 제시한다.

• Journal of the Korea Computer Graphics Society
• /
• v.17 no.3
• /
• pp.9-19
• /
• 2011

Computing triangle-triangle intersections has been a fundamental task required for many 3D geometric problems. We propose a novel robust GPU algorithm to efficiently compute intersections in a large triangle set. The algorithm has three stages:k-d tree construction, triangle pair generation, and exact intersection computation. All three stages are executed on GPU except, for unsafe triangle pairs. Unsafe triangle pairs are robustly handled by CLP(controlled linear perturbation) on a CPU thread. They are identified by floating-point filtering while exact intersection is computed on GPU. Many triangles crossing a split plane are duplicated in k-d tree construction, which form a lot of redundant triangle pairs later. To eliminate them efficiently, we use a split index which can determine redundancy of a pair by a simple bitwise operation. We applied the proposed algorithm to computing 3D Minkowski sum boundaries to verify its efficiency and robustness.

• Journal of the Korea Computer Graphics Society
• /
• v.7 no.2
• /
• pp.1-9
• /
• 2001

본 논문은 여러 장의 이미지로부터 삼차원 모델을 빠르게 복원하기 위한 다각형 기반 Space Carving 알고리즘을 제안한다. 본 논문에서 제안하는 알고리즘은 기존의 복셀 carving 연산에 다각형 carving 연산을 추가하여 기존 복셀 carving 기법의 단점인 렌더링 품질의 저하와 느린 렌더링 속도 문제를 보완하였다. 따라서 복원된 모델은 다각형 구조를 가지며, 이로부터 텍스쳐 매핑을 이용한 빠른 속도의 고품질 렌더링 기법이 가능해진다. 또한 다각형 carving 후잉여 데이터를 삭제함으로써 복원된 모델의 품질 저하없이 메모리를 줄이고, 더욱 빠른 렌더링을 가능하게 한다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2006.10a
• /
• pp.158-161
• /
• 2006

현대 영상산업에서 컴퓨터 그래픽스가 차지하는 비중은 크게 늘어나고 있다. 컴퓨터 그래픽스 기술의 발달로 인한 디지털 영화나 애니메이션이 점차 증가함에 따라 이러한 장면이 등장하는 가상캐릭터를 쉽게 접할 수 있다. 이런 가상 캐릭터를 이용하여 가상 해저 환경을 생성하기 위해서는 3D 모델링 및 애니메이션 기술을 개발해야 한다. 국내에서는 가상 해저 환경을 구축하여 실감 체험을 할 수 있는 VR 콘텐츠 기술 개발에 관련하여 군중 장면 처리 및 군중 행동 시스템의 설계 및 구현 등의 연구가 있었으나 군중 행동 모델러 기술 개발을 실용화 할 단계까지는 미치지 못하고 있다. 본 논문에서는 가상 해저환경에 존재하는 다수의 캐릭터의 움직임을 수작업으로 제공하는 것이 시간과 비용이 많이 소요되기 때문에 이를 자동화하여 보다 사실적이고 효율적인 가상 해저환경 속에서 군중 행동 장면을 생성하기 위해서 Fish 군중 행동 모델러 기술을 개발한다.

• Cartoon and Animation Studies
• /
• s.36
• /
• pp.147-165
• /
• 2014

Around the turn of 21st century, there has been a major technological shift in the animation industry. With development of reality-based computer graphics, major American animation studios replaced hand-drawn method with the new 3D computer graphics. Traditional animation was known for its simplified shapes such as circles and triangle that makes characters' movements distinctive from non-animated feature films. Computer-generated animation has largely replaced it, but is under continuous criticism that automated movements and reality-like graphics devaluate the aesthetics of animation. Although hand-drawn animation is still produced, 3D computer graphics have taken commercial lead and there has been many changes to acting of animated characters, which calls for detailed investigation. Firstly, the changes in acting of 3D characters can be traced from looking at human-like rigging method that mimics humanistic moving mechanism. Also, if hair and clothing was part of hand-drawn characters' acting, it has now been hidden inside mathematical simulation of 3D graphics, leaving only the body to be used in acting. Secondly, looking at "Stretch and Squash" method, which represents the distinctive movements of animation, through the lens of media, a paradox arises. Hand-drawn animation are produced frame-by-frame, and a subtle change would make animated frames shiver. This slight shivering acts as an aesthetic distinction of animated feature films, but can also require exaggerated movements to hide the shivering. On the contrary, acting of 3D animation make use of calculated movements that may seem exaggerated compared to human acting, but seem much more moderate and static compared to hand-drawn acting. Moreover, 3D computer graphics add the third dimension that allows more intuitive movements - maybe animators no longer need fine drawing skills; what they now need is directing skills to animate characters in 3D space intuitively. On the assumption that technological advancement and change of artistic expressionism are inseparable, this paper compares acting of 3D animation studio Pixar and classical drawing studio Disney to investigate character acting style and movements.

• The KIPS Transactions:PartA
• /
• v.10A no.2
• /
• pp.149-156
• /
• 2003

In the latest medical world, the attempt of reconstructing anatomical human body system using computer graphics technology awakes people's interests. Actually, this trial has been made in dentistry too. There are a lot of practicable technology fields using computer graphics in dentistry For example, 3D visualization and measurement of dental data, detection of implant location, surface reconstruction for restoring artificial teeth in prostheses and relocation of teeth in orthodontics can be applied. In this paper, we propose methods for definitely detecting the geometric features of teeth such as cusp, ridge, fissure and pit, which have been used as most important characteristics in dental applications. The proposed methods are based on the approximate curvatures that are measured on a 3D tooth model made by scanning an impression. We also give examples of the geometric features detected by using the proposed methods. Comparing to other traditional methods visually, the methods are very useful in detecting more accurate geometric features.

• Journal of the Korea Computer Graphics Society
• /
• v.15 no.2
• /
• pp.35-40
• /
• 2009

In this paper, we present the web3D-based virtual reality(VR) system for the safety education of the hydrogen station. Currently, hydrogen is considered the next generation energy, and hydrogen station is a part of core infrastructure in hydrogen industry. However, the experience of safety equipment in the hydrogen station is limited to the non-experts, because it is a restricted area in general industry. Therefore, using the event driven method, we develop the VR system to transfer the information of hydrogen station to the non-experts. Using our system, user experiences the safety concerns in the hydrogen station, and also learn the informations of hydrogen energy.