• Journal of Korea Game Society
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• v.13 no.2
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• pp.99-110
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• 2013

As volume rendering has been applied for computer game, the visualization of volume data with surface data in one scene has been required. Though a hybrid rendering of volume and surface data have been developed using the GPGPU functionality, computer games which run on low-level hardware are difficult to perform the hybrid rendering. In this paper, we propose a new hybrid rendering based on DirectX 9.0 and general hardware. We generate the layered depth images from surface data using a new method to reduce the depth complexity and generation time. Then, we perform the hybrid rendering using the layered depth images. In the rendering process, we suggest a new method to transform the coordinate system from a surface coordinate to a volume coorinate and propose an accelerated rendering technique. As the result, we can perform volume-surface hybrid rendering in an efficient way.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.449-454
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• 2009

The human face has "expression" as an important visual factor in contrast with general objects. For this reason, cartoonists draw shadow that emphasizes facial shape and facial expression in order to convey atmosphere of scene and trait of character. This shadow should be considered when doing cartoon rendering for facial expression although it is not an physical shading. This paper proposes a cartoon rendering system for facial expression based on shading techniques of real cartoonist. First of all, we searched such techniques of cartoonist through variety of collected cartoon images and defined shadow templates according to character's facial expression to do cartoon rendering diffently. After that, we demonstrated cartoon rendering system of facial expression on the basis of survey result that effectively emphasizes facial shape and facial expression. Finally, we showed the usefulness through the user questionnaire.

• Korean Journal of Computational Design and Engineering
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• v.5 no.4
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• pp.347-358
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• 2000

The view dependency of typical spatial-partitioning based NC simulation methods is overcome by polygon rendering technique that generates polygons to represent the workpiece, thus enabling dynamic viewing transformations without reconstruction of the entire data structure. However, the polygon rendering technique still has difficulty in realizing real-time simulation due to unsatisfactory performance of current graphics devices. Therefore, it is necessary to develop a mesh decimation method that enables rapid rendering without loss of display quality. In this paper. we proposed a new mesh decimation algorithm thor a workpiece whose shape varies dynamically. In this algorithm, the 2-map data thor a given workpiece is divided into several regions, and a triangular mesh is constructed for each region first. Then, if any region it cut by the tool, its mesh is regenerated and decimated again. Since the range of mesh decimation is confined to a few regions, the reduced polygons for rendering can be obtained rapidly. Our method enables the polygon-rendering based NC simulation to be applied to the computers equipped with a wider range of graphics cards.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.1843-1849
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• 2009

In real-time 3D Graphics, pipeline optimization is one of techniques enhancing rendering performance. Pipeline optimization is kind of buffer reordering problem, but it is NP-hard. Therefore techniques that is approximating optimal solution and suitable for real-time 3D graphics are needed. This paper analyze pattern of rendering states changing costs for real-time 3D graphics, and based on this, the algorithm that brings rendering states into line by changing costs is proposed. The proposed technique shows good performance enhancement when costs of some rendering states are much higher than others. Proposed technique shows 2.5 to 4 times better performance than non-ordering algorithm and becomes more faster when rendering costs of a state gets higher.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.1899-1902
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• 2003

Recently several methods have been developed for the virtual space construction. Generally, most of the methods are geometric-based rendering technic, but they are difficult to construct real-time rendering because of large data. In this paper, we present a three dimension image-based rendering method that enable a constant speed of real-time rendering regardless of object complexity in virtual space. The Proposed method shows good performance for the virtual space construction with high complexity.

• The KIPS Transactions:PartB
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• v.13B no.3 s.106
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• pp.295-300
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• 2006

The integral imaging system is an auto-stereoscopic display that allows users to see 3D images without wearing special glasses. In the integral imaging system, the 3D object information is taken from several view points and stored as elemental images. Then, users can see a 3D reconstructed image by the elemental images displayed through a lens array. The elemental images can be created by computer graphics, which is referred to the computer-generated integral imaging. The process of creating the elemental images is called image mapping. There are some image mapping methods proposed in the past, such as PRR(Point Retracing Rendering), MVR(Multi-Viewpoint Rendering) and PGR(Parallel Group Rendering). However, they have problems with heavy rendering computations or performance barrier as the number of elemental lenses in the lens array increases. Thus, it is difficult to use them in real-time graphics applications, such as virtual reality or real-time, interactive games. In this paper, we propose a new image mapping method named VVR(Viewpoint Vector Rendering) that improves real-time rendering performance. This paper describes the concept of VVR first and the performance comparison of image mapping process with previous methods. Then, it discusses possible directions for the future improvements.

• Journal of Korea Multimedia Society
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• v.12 no.4
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• pp.512-520
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• 2009

Maximum intensity projection (MIP) is a volume rendering method which extracts maximum values along the viewing direction through volume data. It visualizes high-density structures, such as angio-graphic datasets so that it is frequently used in medical imaging systems. We have proposed an efficient two-step MIP acceleration method that uses the recent CPUs. First, we exploited SIMD instructions to reduce conditional branch instructions which take up a considerable part of whole rendering process, so that we improved rendering speed. Second, we proposed a new method, which accesses volume and image data successively by modifying the shear-warp rendering. This method improves memory access patterns so that cache misses are reduced. Using the current CPUs, our method improved the rendering speed by a factor of 7 than that of the shear-warp rendering.

• Journal of Digital Contents Society
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• v.9 no.4
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• pp.771-778
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• 2008

A Device performance analyzing method for appropriate level in hybrid rendering model is suggested. In recent research, we proposed a hybrid rendering model which is applying a proper shading method to each of polygons consisting of an object. The number of polygon for Gouraud shading and that for flat shading should be considered according to a current device performance and system environments. Therefore, this paper suggests the method to calculate automatically a proper resolution of a mesh of object and a proper level of mixture between Gouraud and a flat shading, considering a current device performance and a preference of end-user. The rendering model is so simple that it can be an efficient replacement to reduce a real-time rendering time since it provides automatically multi-level of rendering resolution to an executing environments. Moreover, it can be adopted in real-time adaptive service for 3D graphic contents like a graphic game under various device environments.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.1
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• pp.94-101
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• 2004

The gross composition, gross amino acid content, apparent ileal amino acid digestibility and apparent ileal digestible amino acid content from 64 commercially produced meat and bone meals were statistically analysed. The samples were produced by 22 plants over a 2.5 year period with eight plants using batch dry rendering and 14 plants using low temperature rendering. A linear model with method and time of year (period) as fixed effects, plant within method as a random effect and sheep percent as a covariate was fitted to the composition data. The majority of the variation in the gross composition, amino acid digestibility and digestible amino acid content was explained by differences between plants using the same method. Neither rendering season nor origin of the raw materials contributed significantly to the observed variation in meat and bone meal protein quality. Rendering method (low temperature or batch rendering) had a significant effect on the variation observed in gross fat content, gross energy content, pepsin nitrogen digestibility, protein solubility and total lanthionine content. The digestibility of a number of amino acids and the apparent digestible content of arginine, cysteine, aspartic acid, proline and hydroxyproline were also significantly affected by rendering method. On average, batch dry and low temperature rendering systems produce meat and bone meals of similar nutritional quality. The variation between plant and within plant, however, is large, indicating that purchasing meat and bone meal from the same plant does not guarantee a consistent quality.

• Journal of Korea Multimedia Society
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• v.10 no.3
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• pp.316-324
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• 2007

Maximum Intensity Projection (MIP) identifies patients' anatomical structures from MR or CT data sets. Recently, it becomes possible to generate MIP images with interactive speed by exploiting Graphics Processing Unit (GPU) even in large volume data sets. Generally, volume boundary plane is obliquely crossed with view-aligned texture plane in hardware-texture based volume rendering. Since the ray sampling distance is not increased at volume boundary in volume rendering, the aliasing problem occurs due to data loss. In this paper, we propose an efficient method to overcome this problem by Re-rendering volume boundary planes. Our method improves image quality to make dense distances between samples near volume boundary which is a high frequency area. Since it is only 6 clipping planes are additionally needed for Re-rendering, high quality rendering can be performed without sacrificing computational efficiency. Furthermore, our method couldbe applied to Minimum Intensity Projection (MinIP) volume rendering.