• Journal of Korea Game Society
• /
• v.20 no.3
• /
• pp.75-84
• /
• 2020

This paper introduces an interactive indirect illumination algorithm which considers indirect visibility. First, a small number of rays are emitted on hemisphere of the current pixel to obtain the first intersection. If this point is directly illuminated by the light source, its illuminated color is collected. Second, in order to approximate the indirect visibility, a 3D ray marching algorithm, which is based on a hierarchy structure, is used to accelerate the ray-voxel intersection. Third, the indirect images are denoised by an edge-avoiding filtering with a local means replacement method.

• KIPS Transactions on Computer and Communication Systems
• /
• v.5 no.9
• /
• pp.237-246
• /
• 2016

DIBR (Depth Image Based Rendering) is a multimedia technology that generates the virtual multi-view images using a color image and a depth image, and it is used for creating glasses-less 3-dimensional display contents. This research describes the effect of depth accuracy about the objective quality of DIBR-based multi-view images. It first evaluated the minimum depth quantization bit that enables the minimum distortion so that people cannot recognize the quality degradation. It then presented the comparative analysis of non-uniform domain-division quantization versus regular linear quantization to find out how effectively express the accuracy of the depth information in same quantization levels according to scene properties.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2014.10a
• /
• pp.818-819
• /
• 2014

Recently there are many works conducted on utilizing the DIBR (Depth-Image-Based Rendering) based intermediate images for the three-dimensional displays that do not require the use of stereoscopic glasses. However the prior works have used expensive depth cameras to obtain high-resolution depth images since DIBR-based intermediate image generation method requires the accuracy for depth information. In this study, we have developed the simulation to generate multi-view intermediate images based on the depth and color images using Microsoft Kinect. This simulation aims to support the acquisition of multi-view intermediate images utilizing the low-resolution depth and color image from Kinect, and provides the integrated service for the quality evaluation of the intermediate images. This paper describes the architecture and the system implementation of this simulation program.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2022.06a
• /
• pp.150-153
• /
• 2022

최근 XR은 LED스크린의 VR과 그 LED 스크린의 외부영역을 AR 그래픽으로 덮는 방법으로 LED에서 표현되는 VR영상과 확장된 AR의 효과로 LED VR의 확장의 개념으로 가상환경 제작으로서 많이 시도 되고 있다. 그러나, 여전히 LED 스크린의 VR에서 어떤 가상의 객체가 AR로 튀어 나올 때 타이밍을 맞추어 전환해야 할 경우 부자연스럽거나 동기가 맞지 않아 합성결과가 어긋나 품질이 떨어지며, 여러 객체를 동시에 수동으로 전환시켜야 할 때 객체의 제어에 어려움이 많을 수 있다. 본 논문에서는 그래픽 오브젝트가 VR과 AR의 경계를 오갈 때 자동으로 자연스럽게 전환/합성 가능하도록 하는 'Culling 박스'와 또, 여러 렌더링 머신에서 같은 오브젝트 제어를 동시에 제어 가능한 'TCP/IP 기반의 원격제어 UI'를 설명한다. 컬링박스는 전환해야 할 객체가 많은 복잡한 장면에서 모든 오브젝트가 일정 경계에서 자동으로 전환되며, 원격제어 UI의 타임라인 에디터와 이벤트 제어메뉴 UI를 통하여, 각각의 다른 머신의 시퀀스 및 오브젝트들을 제어 가능하여 효율적인 XR제작이 가능함을 확인 하였다.

• Archives of design research
• /
• v.18 no.3 s.61
• /
• pp.15-24
• /
• 2005

There is a large waste of time, money, and production through the infelicitous product design process in small and medium enterprises. They don't possess enough career-manpower with respect to design. Especially, the objective and scientific approach process isn't presented very well on the 'establishment concept' of the embodiment phase or 'Sketch and Rendering' of the development phase which are the most important design processes. So, this research is applied to the conception of the AHP method. It uses the basic concept of relativity to decrease risk from the calculational quantity data, and supplement the decision making phase. Generally, human beings can conclude by relative judgement which is more influenceable than absolute judgement. So we must use the relative comparison concept rather than the comparison of two items with variable sketches based on characteristics of human beings. Thus, efficiency judgement is dependent on design sketch comparisons which help the consistency progress of variable alternative plans. We can decrease risk when we chose the final design and increase efficiency of the design decision making. That is now a perfect selection of each alternative's ranking and sensitive design result but this research will provide consistency criterion on filtering and lead to variable design alternatives. The significance of this research is the efficiency method that overcomes differences of character and sensitivity on many phases of the process. Finally, this research proposes a new ideal process that where applied improves quality and evidence of propriety through comparison to existing methods result in method application research for improvement quality.

• Journal of KIISE
• /
• v.44 no.3
• /
• pp.332-337
• /
• 2017

When using IFC data consisting of STEP schema based on the EXPRESS language, it is not easy for collaborating project stakeholders to share BIM modeling shape information. The IFC viewer application must be installed on the desktop PC to review the BIM modeling shape information defined within the IFC, because the IFC viewer application not only parse STEP structure information model but also process the 3D feature construction for a 3D visualization. Therefore, we propose a lightweight data structure design for web visualization by parsing IFC data and constructing 3D modeling data. Our experimental results show the weight reduction of IFC data is about 40% of original file size and the web visualization is able to see the same quality with all web browsers which support WebGL on PCs and smartphones. If applied research is conducted about the web visualization based on IFC data of the last construction phase, it could be utilized in various fields ranging from the facility maintenance to indoor location-based services.

• Journal of the Korea Computer Graphics Society
• /
• v.24 no.3
• /
• pp.61-71
• /
• 2018

When triangular meshes are generated from the point clouds in global space reconstructed through camera pose estimation against captured RGB-D streams, the quality of the resulting meshes improves as more triangles are hired. However, for 3D reconstructed models beyond some size threshold, they become to suffer from the ugly-looking artefacts due to the insufficient precision of RGB-D sensors as well as significant burdens in memory requirement and rendering cost. In this paper, for the generation of 3D models appropriate for real-time applications, we propose an effective technique that extracts high-quality textures for moderate-sized meshes from the captured colors associated with the reconstructed point sets. In particular, we show that via a simple method based on the mapping between the 3D global space resulting from the camera pose estimation and the 2D texture space, textures can be generated effectively for the 3D models reconstructed from captured RGB-D image streams.

• Journal of KIISE:Computer Systems and Theory
• /
• v.30 no.11
• /
• pp.675-690
• /
• 2003

In this paper, we present the virtual dancing studio for distributed virtual environment. In this system, geographically distributed user shares the virtual dancing hall and interacts with each other. The participating object can be a graphical avatar or a live video stream. It allows the coexistence of graphic objects and real images in the shared virtual space. One of the main technical challenges in developing the distributed virtual environment is to handle excessive network traffic. In an effort to effectively reduce the network traffic, we propose a scheme to adjust the QoS of each object with respect to the distance from the observer in the virtual space. The server maintains the QoS vector for each client's shared space and controls the packet traffic to individual clients based on its QoS vectors. We develop a proto-type virtual dancing environment. Java based development enables the client to be platform independent. The result of experiment shows that the adoption of hierarchical QoS management significantly reduces the overall network traffic.

• Journal of the Korea Computer Graphics Society
• /
• v.22 no.2
• /
• pp.1-10
• /
• 2016

The computational cost of clothing simulation and rendering is mainly depends on the type of mesh and its quality. Thus, quadrilateral meshes are generally preferred over triangular meshes for the reasons of accuracy and efficiency. This paper presents a method of quadrangulating sewing pattern based on the recursive geometry decomposition method. Herein, we proposed two simple improvements to the previous algorithms. The first one deals with the recursive geometry decomposition in which the physical domain is decomposed into simple and mappable regions. The second proposed algorithm deals with the vertex validation in which the invalid vertex classification can be validated.

• Journal of Korea Game Society
• /
• v.15 no.5
• /
• pp.99-108
• /
• 2015

To identify the location of the object and improve the realism in 3D game, shadow mapping is widely used to compute the depth values of vertices in view of the light position. Since the depth value of the shadow map is calculated by the world coordinate, the depth values of the static object don't need to be updated. In this paper, (1) in order to improve the rendering speed, using multiple render targets the depth values of static objects stored only once are separated from those of dynamic objects stored each time. And (2) in order to improve the shadow quality in the quarter view 3D game, the position of the light is located close to dynamic objects traveled along the camera each time. The effectiveness of the proposed method is verified by the experiments according to the different static and dynamics object configuration in 3D game.