• Korean Journal of Computational Design and Engineering
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• v.19 no.3
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• pp.294-304
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• 2014

This paper presents a real-time rendering algorithm of large-scale geometric data using GLSL (OpenGL shading language). It details the VAO (vertex array object) and VBO(vertex buffer object) to be used for up-loading the large-scale point clouds and polygon meshes to a graphic video memory, and describes the shader program composed by a vertex shader and a fragment shader, which manipulates those large-scale data to be rendered by GPU. In addition, we explain the global rendering procedure that creates and runs the shader program with the VAO and VBO. Finally, a rendering performance will be measured with application examples, from which it will be demonstrated that the proposed algorithm enables a real-time rendering of large amount of geometric data, almost impossible to carry out by previous techniques.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1003-1006
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• 2005

Vertex shader of GPU in personal computer is advanced in functions as to be half of traditional fixed T&L functions. And, capacity of memory for saving resources to process instructions is unlimited. GPU that can be programmed by programmer is needed for mobile system as well as personal computer. In this paper, we implement software virtual machine for vertex shader using C++ Language. Our goal is designing hardware GPU that can apply to mobile system. The virtual machine consists of nVidia GPU instructions. Input Data to virtual machine is generated by Microsoft fxc compiler. That is to say, Input Data is compiled shader program written in HLSL, Cg, or ASM. The virtual machine will be a reference model for designing hardware GPU and can be used for Testbed to test added or modified instruction.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.1
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• pp.145-149
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• 2015

A reconfigurable lighting engine for widely used lighting models is proposed for low-power GPU shaders. Conventionally, lighting operations that involve many complex arithmetic operations were calculated by the shader programs on the GPU, which led to a significant energy overhead. In this letter, we propose a lighting engine to improve the energy-efficiency by supporting the widely used advanced lighting models in hardware. It supports the Blinn-Phong, Oren-Nayar, and Cook-Torrance models, by exploiting the logarithmic arithmetic and optimizing the trigonometric function evaluations for the energy-efficiency. Experimental results demonstrate 12.7%, 42.5%, and 35.5% reductions in terms of power-delay product from the shader program implementations for each lighting model. Moreover, our work shows 10.1% higher energy-efficiency for the Blinn-Phong model compared to the prior art.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.1025-1030
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• 2007

여러 학계와 산업계로부터 인체영상과 같은 정적인 볼륨 데이터뿐만 아니라, 유체 흐름과 같은 동적으로 움직이는 Time-Variant 볼륨 데이터에 대한 실시간 렌더링의 요구가 계속되고 있다. 일반적으로 Time-Variant 데이터는 그 크기가 정적 볼륨 데이터의 수배에서 수백 배에 이르러, 이를 실시간으로 가시화하는 데에 많은 어려움이 있어왔다. 한편, PC 그래픽스 하드웨어의 급격한 발전에 따라 슈퍼컴퓨터나 다수의 컴퓨터들을 이용한 병렬/분산 렌더링으로나 가능했던 Time-Variant 볼륨 데이터의 실시간 볼륨 렌더링을 한대의 일반 PC에서 수행하려는 시도가 계속되고 있다. GPU의 꼭지점 및 프래그먼트 쉐이더(vertex & fragment shader)는 수치 계산에 최적화된 벡터 연산과 사용자 프로그래밍 기능으로 빠른 볼륨 렌더링을 일반 PC에서도 가능하게 했다. 본 논문에서는 GPU를 이용해서 Time-Variant 볼륨 데이터를 빠르게 가시화하고, 이렇게 개발한 GPU 볼륨 렌더링 프로그램을 사용자가 사용하기 편리하도록 사용자 친화적인 유저 인터페이스를 설계하고 구현하였다. 특히, 시간에 따라 동적으로 변화해야 하는 전이함수를 최대한 편리하게 생성할 수 있도록 전이함수 에디터에 중점을 두었다.

• Journal of Broadcast Engineering
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• v.25 no.5
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• pp.655-664
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• 2020

Free viewpoint image synthesis technology is one of the important technologies in the MPEG-I (Immersive) standard. RVS (Reference View Synthesizer) developed by MPEG-I and in use in MPEG group is a DIBR (Depth Information-Based Rendering) program that generates an image at a virtual (intermediate) viewpoint from multiple viewpoints' inputs. RVS uses the mesh surface method based on computer graphics, and outperforms the pixel-based ones by 2.5dB or more compared to the previous pixel method. Even though its OpenGL version provides 10 times speed up over the non OpenGL based one, it still shows a non-real-time processing speed, i.e., 0.75 fps on the two 2k resolution input images. In this paper, we analyze the internal of RVS implementation and modify its structure, achieving 34 times speed up, therefore, real-time performance (22-26 fps), through the 3 key improvements: 1) the reuse of OpenGL buffers and texture objects 2) the parallelization of file I/O and OpenGL execution 3) the parallelization of GPU shader program and buffer transfer.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.6
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• pp.1229-1238
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• 2023

Digital twin is a technology that creates a virtual space that replicates the real world and manages the real world efficiently by integrating the real and virtual spaces. The digital twin concept for water facilities is to effectively manage water pipes in the real world by implementing them in a virtual space and augmenting them to the interior space of the building. In the proposed method, the Unity 3D game engine is used to implement the application of digital twin technology in the interior of a building. The AR Foundation toolkit based on ARCore is used as the augmented reality technology for our Digital Twin implementation. In digital twin applications, it is essential to match the real and virtual worlds. In the proposed method, 2D image markers are used to match the real and virtual worlds. The Unity shader program is also applied to make the augmented objects visually realistic. The implementation results show that the proposed method is simple but accurate in placing water pipes in real space, and visually effective in representing water pipes on the wall.