• Journal of the Korea Computer Graphics Society
• /
• v.18 no.1
• /
• pp.11-21
• /
• 2012

Point-based rendering has gained much attention as an alternative to polygon-based rendering because of its simplicity and flexibility. However, current point-based rendering techniques do not provide a sufficient rendering quality for translucent materials such as human skin. In this paper, we propose a point-based rendering framework with subsurface scattering of light, which is important to create the soft and semi-translucent appearance of human skin. To accurately simulate subsurface scattering in multi-layer materials, we present splat-based diffusion to apply a linear combination of several Gaussian basis functions to each splat in object space. Compared to existing point-based approaches, our method offers a significantly improved visual quality in rendering human faces.

• The KIPS Transactions:PartA
• /
• v.10A no.5
• /
• pp.425-432
• /
• 2003

This paper presents an EMR(Electronic Medical Record) chart for efficient PDA through the quad tree image rendering based on the mobile. Using the intermediate image space algorithm instead of the final one for volume rendering, we have solved the probems of th eholes coming from the point-to-point to mapping. The quad-tree based on the delta-tree efficiently represents volume expressions and results in higher compression effects. With the volume rendering, we can decrease the rendering time and get a higher quality and efficiency for PDA through image based rendering.

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

• Proceedings of the Korean Information Science Society Conference
• /
• 2005.11a
• /
• pp.712-714
• /
• 2005

본 논문은 효율적인 점 기반 렌더링(Point-based Rendering)을 위해 확장 이차 오류 척도(Quadric Error Metrics) 기법을 이용하는 간략화 알고리즘을 제안한다. 점 기반 렌더링의 기본 개념은 자유곡면을 메쉬와 같은 연결정보 없이 직접 점들로 표현하고, 렌더링하는 것이다. 확장 이차 오류 척도 기법은 메쉬를 간략화 하는데 있어 기하 정보뿐만 아니라 색상, 텍스쳐 좌표 정보까지 고려하여 간략화 하는 알고리즘이다. 이 연구는 3차원 점 데이터로부터 복원한 폴리곤 메쉬 모델로부터 효율적인 점 기반 렌더링(Point-based Rendering)을 위해 기하 정보 및 색상 정보까지 고려하여 원본 점 데이터를 간략화 하는 저용량의 효율적인 점 기반 렌더링 알고리즘을 제안하고, GPU 기반 렌더링 결과를 보였다.

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

• Journal of Multimedia Information System
• /
• v.5 no.1
• /
• pp.59-62
• /
• 2018

The delay between input action and visual interface feedback ("Latency") in a touchscreen inking task reduces the user's performance. When the latency is less than 2.38ms, the user cannot perceive the latency in dragging task. This value is difficult to achieve on recent touchscreens and general purpose computers. So, methods of predicting touch points to reduce perceptible latency has been proposed. In general, touch points prediction is not perfect. When using point prediction, feedback of the predicted points is displayed on the screen, after a while, erased when the actual points are displayed. When this task is implemented by software, it causes additional latency to work to erase predicted points feedback. It therefore propose a platform for rendering point prediction feedback without additional latency by the FPGA. This platform transmits input points and HDMI signals rendering feedback of input points to the FPGA. The FPGA draws the feedback of points predicted based on the input points on the HDMI and displays the screen. Since hardware rendering changes the HDMI signal every frame, it does not require erasing work and rendering can be done within an early time regardless of the amount of rendering, so we will reduce the latency.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.23 no.6
• /
• pp.542-553
• /
• 2020

Virtual world and simulation need large scale map rendering. However, rendering too many vertices is a computationally complex and time-consuming process. Some game development companies have developed 3D LOD objects for high-speed rendering based on distance between camera and 3D object. Terrain physics simulation researchers need a way to recognize the original object shape from 3D LOD objects. In this paper, we proposed simply automatic LOD framework using point cloud data (PCD). This PCD was created using a 6-direct orthographic ray. Various experiments are performed to validate the effectiveness of the proposed method. We hope the proposed automatic LOD generation framework can play an important role in game development and terrain physic simulation.

• Journal of Korea Multimedia Society
• /
• v.14 no.10
• /
• pp.1229-1237
• /
• 2011

The volume ray-casting method is one of the direct volume rendering methods that produces high-quality images as well as manipulates semi-transparent object. Although the volume ray-casting method produces high-quality image by sampling in the region of interest, its rendering speed is slow since the color acquisition process is complicated for repetitive memory reference and accumulation of sample values. Recently, the GPU-based acceleration techniques are introduced. However, they require pre-processing or additional memory. In this paper, we propose efficient point-primitive based method to overcome complicated computation of GPU ray-casting. It presents semi-transparent objects, however it does not require preprocessing and additional memory. Our method is fast since it generates point-primitives from volume dataset during sampling process and it projects the primitives onto the image plane. Also, our method can easily cope with OTF change because we can add or delete point-primitive in real-time.

• International Journal of Internet, Broadcasting and Communication
• /
• v.14 no.3
• /
• pp.276-284
• /
• 2022

In this paper, we implemented cloud rendering using WebRTC for high-quality AR and VR services. Cloud rendering is an applied technology of cloud computing. It efficiently handles the rendering of large volumes of 3D content. The conventional VR and AR service is a method of downloading 3D content. The download time is delayed as the 3D content capacity increases. Cloud rendering is a streaming method according to the user's point of view. Therefore, stable service is possible regardless of the 3D content capacity. In this paper, we implemented cloud rendering using WebRTC and analyzed its performance. We compared latency of 100MB, 300MB, and 500MB 3D AR content in 100Mbps and 300Mbps internet environments. As a result of the analysis, cloud rendering showed stable latency regardless of data volume. On the other hand, the conventional method showed an increase in latency as the data volume increased. The results of this paper quantitatively evaluate the stability of cloud rendering. This is expected to contribute to high-quality VR and AR services

• Journal of Korea Multimedia Society
• /
• v.16 no.4
• /
• pp.520-528
• /
• 2013

Makeup simulation is a tool that tests various makeup methods on a virtual digital face using input and display devices. Although several simulation systems supporting various makeup styles have been recently developed, most systems have many limitations on realistic skin representations because they use 2D facial images. We develope a realistic makeup simulation method which can control skin reflectance and roughness parameters. The method allows a user to simulate makeup applications while changing skin parameters using high-resolution facial data acquired by 3D scanners. Besides we use a point-based shape representation which enables simple and flexible 3D rendering, and provide a more realistic makeup simulation by applying different skin parameters on each part of the face.