• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2006년도 하계종합학술대회
• /
• pp.989-990
• /
• 2006

This paper presents a design of 3D Graphics Geometry processor. A geometry processor needs to cope with a large amount of computation and consists of transformation processor and lighting processor. To deal with the huge computation, a vector processing structure based on pipeline chaining is proposed. The proposed geometry processor performs 4.3M vertices/sec at 100MHz using 11 floating-point units.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2005년도 추계종합학술대회
• /
• pp.917-920
• /
• 2005

This paper presents 3D graphics geometry processor for mobile applications. Geometry stage needs to cope with the large amount of computation. Geometry stage consists of transformation process and lighting process. To deal with computation in geometry stage, the vector processor that is based on pipeline chaining is proposed. The performance of proposed 3D graphics geometry processor is up to 4.3M vertex/sec at 100 MHz. Also, the designed processor is compliant with OpenGL ES that is widely used for standard API of embedded system. The proposed structure can be efficiently used in 3D graphics accelerator for mobile applications.

• 대한전자공학회논문지SD
• /
• 제43권2호
• /
• pp.24-33
• /
• 2006

본 논문에서는 휴대용 정보기기 시스템에서 더욱 향상된 실시간 3D 그래픽 가속 능력을 갖는 SoC 구현을 위해 효과적인 3D 그래픽 Geometry 처리 IP 구조를 연구하였다. 이를 기반으로 3D 그래픽 Geometry 처리 과정에 필요한 부동소수점 연산기를 설계하였으며, 내장형 3D 그래픽 국제 표준인 OpenGL-ES를 지원하는 부동소수점 Geometry 프로세서를 설계하였다. 설계된 Geometry 프로세서는 Xilinx-Vertex2 FPGA에서 160k gate의 면적으로 구현되었으며, 80 MHz의 동작주파수 환경에서 실제 3D 그래픽 데이터를 이용하여 Geometry 처리 과정의 성능 측정 실험을 하였다. 실험 결과 80 MHz의 동작주파수에서 초당 1.5M 개의 폴리곤 처리 성능이 확인되었으며, 이는 타 3D 그래픽 가속 프로세서에 비하여 평균 2배 이상의 Geometry 처리 성능이다. 본 지오메트리 프로세서는 Hynix 0.25um CMOS 공정에 의한 측정결과 83.6mW의 소모전력을 나타낸다.

• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 2000년도 가을 학술발표논문집 Vol.27 No.2 (3)
• /
• pp.15-17
• /
• 2000

3차원 그래픽 가속기는 기하학 처리(Geometry processing) 단계와 래스터라이제이션(rasterization) 단계로 구성되어 있다. 기존의 기하학 처리 방식에서는 꼭지점의 좌표계산과 빛의 효과를 계산하는 일련의 단계들이 순차적으로 수행되었는데 이는 많은 양의 폴리곤 처리가 요구되는 현재의 어플리케이션 환경에서 상당한 오버헤드로 작용한다. 본 연구에서는 기하학 처리 파이프라인을 보다 고속으로 처리하기 위해 라이팅 단계를 다른 단계들과 병렬적으로 수행할 수 있는 구조를 제안한다. 실험결과 제안하는 중첩 라이팅 방식의 기하학 처리기(Overlapped lighting geometry processor, OLGP)는 기존의 순차적인 기하학 처리기(Sequential geometry processor, SeqGp)에 비해 최대 21%의 수행 성능 향상을 보였다.

• 한국정보처리학회논문지
• /
• 제7권1호
• /
• pp.252-265
• /
• 2000

본 논문에서는 3차원 그래픽의 처리 과정 중 부동 소수점 연산이 많은 소요되는 geometry 프로세싱 처리 방법과 계산량을 단계별로 분석하였다. 그리고, 그래픽 프로세싱의 수행 특성을 추출하여, 이에 맞는 기능 유닛을 설계하고, 데이터 처리 방안과 제안하는 geometry 프로세서의 구조를 설명한 다음, 성능을 분석하였다. 제안하는 geometry 프로세서는 부동 소수점 덧셈, 곱셈, 나눗셈 연산을 동시에 수행 가능하며, geometry 프로세싱 전 단계를 수행하는데 23.5%의 성능 향상이 있었다. 그리고, 나눗셈/제곱근 연산을 위해서 면적대 성능비가 우수한 SRT 나눗셈 연산기를 추가하여 곱셈 연산기를 이용하는 연산기보다 약 23%의 성능 향상을 이루었다.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
• /
• pp.880-884
• /
• 2002

According to the development of computer technology, especially in 3D graphics and visualization, the interest for 3D GIS has been increasing. Several commercial GIS softwares are ready to provide 3D function in their traditional 2D GIS. However, most of these systems are focused on visualization of 3D objects and supports few analysis functions. Therefore in this paper, we design not only a spatial operation processor which can support spatial analysis functions as well as 3D visualization, but also implement a prototype to operate them. In order to support interoperability between the existing models, the proposed spatial operation processor supports the 3D spatial operations based on 3D geometry object model which is designed to extend 2D geometry model of OGIS consortium, and supports index based on R$^*$-Tree. The proposed spatial operation processor can be applied in 3D GIS to support 3D analysis functions.

• 한국정밀공학회지
• /
• 제17권5호
• /
• pp.116-123
• /
• 2000

This paper presents an NC code post-processor that adjusts feedrates to keep the variation of metal removal rate along the tool paths minimum. Metal removal rate is estimated by virtually machining the part, whose surface model is built from a series of NC codes defined in operation plan, with cutting-tool-assembly models, whose geometry are defined in a machining database. The NC code post-processor modifies the feedrates by the adjustment rules, which are based on the machining knowledge for effective machining. This paper illustrates a procedure fur grouping machining conditions and we also show how to determine an adjustment rule for a machining-condition group. An example part was machined and it shows that the variation of cutting force was dramatically reduced after applying the NC code post-processor. The NC code post-processor is expected to increase productivity while maintaining the quality of the machined part.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2005년도 추계종합학술대회
• /
• pp.711-714
• /
• 2005

We propose floating point arithmetic units for geometry operation of mobile 3D graphic processor. The proposed arithmetic units conform to the single precision format of IEEE standard 754-1985 that is a standard of floating point arithmetic. The rounding algorithm applies the nearest toward zero form. The proposed adder/subtraction unit and multiplier have one clock cycle latency, and the inversion unit has three clock cycle latency. We estimate the required numbers of arithmetic operation for Viewing transformation. The first stage of geometry operation is composed with translation, rotation and scaling operation. The translation operation requires three addition and the rotation operation needs three addition and six multiplication. The scaling operation requires three multiplication. The viewing transformation is performed in 15 clock cycles. If the adder and the multiplier have their own in/out ports, the viewing transformation can be done in 9 clock cycles. The error margin of proposed arithmetic units is smaller than $10^{-5}$ that is the request in the OpenGL standard. The proposed arithmetic units carry out operations in 100MHz clock frequency.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2005년도 추계종합학술대회
• /
• pp.663-666
• /
• 2005

The geometry stage, which performs the transformation and lighting operations of vertices, became the critical part in 3D graphics pipeline. In this paper, we have planned and designed the Geometry Processor for the better and more efficient way to process the real-time 3D using the floating point unit. We also designed a verification system for Geometry engine. It is implemented with Xilinx-Virtex2 and Visual C++.NET. In the Synopsis, we confirmed 100 MHz performance and 137107 cell area of Geometry Engine.

• International Journal of Precision Engineering and Manufacturing
• /
• 제2권3호
• /
• pp.27-33
• /
• 2001

The aim of the present work is to propose a model for Computer Aided programming of numerical Control lathe. This model is based on the concept by features. It has been developed in an Artificial Intelligence environment, that offers a rapidity as well as a precision for NC code elaboration. In this study a pre-processor has been elaborated to study the geometry of turning workpiece. This pre-processor is a hybrid system which combine a module of design by features and a module of features recognition for a piece provided from an other CAD software. Then, we have conceived a processor that is the heart of the CAD/CAM software. The main functions are to study the fixture of the workpiece, to choose automatically manufacturing cycles, to choose automatically cutting tools (the most relevant), to simulate tool path of manufacturing and calculate cutting conditions, end to elaborate a typical manufacturing process. Finally, the system generates the NC program from information delivered by the processor.