• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.414-419
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• 2008

3D rendering is a critical process for a movie production, advertisement, interior simulation, medical and many other fields. Recently, several effective rendering methods have been developed for the photo-realistic image generation. With a rapid performance enhancement of graphics hardware, physically based 3D rendering algorithm can now often be approximated in real-time games. However, the high quality of global illumination, required for the image generation in the 3D animation production community is a still very expensive process. In this paper, we propose a new rendering method to create photo-realistic global illumination effect efficiently by harnessing the high power of the recent GPUs. Final gathering routines in our global illumination module are accelerated by programmable graphics hardware. We also simulate physically based light transport on a ray tracing based rendering algorithm with photon mapping effectively.

• Journal of Power System Engineering
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• v.13 no.2
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• pp.71-82
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• 2009

This paper presents a real-time haptic rendering method for a realistic force feedback in a remote environment with varying communication time-delay. The remote environment is assumed as a virtual environment based on a computer graphics, for example, on-line shopping mall, internet game and cyber-education. The properties of a virtual object such as stiffness and viscosity are assumed to be unknown because they are changed according to the contact position and/or a penetrated depth into the object. The DARMAX model based output estimator is proposed to trace the correct impedance of the virtual object in real-time. The output estimator is developed on the input-output relationship. It can trace the varying impedance in real-time by virtue of P-matrix resetting algorithm. And the estimator can trace the correct impedance by using a white noise that prevents the biased input-output information. Realistic output forces are generated in real-time, by using the inputs and the estimated impedance, even though the communication time delay and the impedance of the virtual object are unknown and changed. The generated forces trace the analytical forces computed from the virtual model of the remote environment. Performance is demonstrated by experiments with a 1-dof haptic device and a spring-damper-based virtual model.

• Journal of the Korea Computer Graphics Society
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• v.7 no.1
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• pp.27-35
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• 2001

Shadows are important elements in producing a realistic image. In rendering. generation of the exact shape and position of shadow is crucial in providing the user with visual cues on the scene. While the shadow map technique quickly generates a shadow for the scene wherein objects and light sources are fixed. it gets slow down as they start to move. In this paper. we apply an image-based rendering technique to generate shadows in real-time using graphics hardware. Due to the heavy requirement of storage for a shadow map repository. we use a wavelet-based compression scheme for effective compression. Our method will be efficiently used in generating realistic scenes in many real-time applications such as 3D games and virtual reality systems.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.8 s.227
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• pp.1116-1124
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• 2004

In these days, a vehicle simulator has been developed with a VR(Virtual Reality) system. A VR system must provide a vehicle simulator with natural interaction, sufficient immersion and realistic images. In addition, a VR system must present a driver with the realistic driving situation. To achieve these, it is important to obtain a fast and uniform rendering performance regardless of the complexity of virtual worlds. In this paper, the factors to improve the reality for the VR based vehicle simulator have been investigated. For the purpose, the modeling and the rendering methods which offer an improved performance for complex VR applications as the 3D road model have been implemented and verified. Then, we experiment on the influence of graphic and sound factors to the driver, and analyze each result for improving the reality such as the driver's viewport, the form of texture, the lateral distance of the side object, and the sound effect. These factors are evaluated on the driving system which is constructed for qualitative analysis. The research results could be used for improving the reality of the VR based vehicle simulator.

• Journal of information and communication convergence engineering
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• v.10 no.2
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• pp.205-209
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• 2012

To manufacture a real time digital holographic display system capable of being applied to next-generation television, it is important to rapidly generate a digital hologram. In this paper, we analyze digital hologram rendering based on a computer computation scheme. We analyze previous recursive methods to identify regularity between the depth-map image and the digital hologram.

• Journal of Korea Multimedia Society
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• v.17 no.9
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• pp.1052-1063
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• 2014

Non-photo realistic Rendering is the one of the fields in Computer Graphics and many painterly rendering techniques have been studying. However studies about a specific painter are still in a rarity. Therefore in this paper, we studied about technique for generation of Henri de Toulouse-Lautrec's portraits. Toulouse-Lautrec was a painter in 19th century. His style of portraits was expressed as follows; the sketch was drawn by conte or pastel in croquis style and colored only focused parts like faces on the base colored area. For simulate this, we propose sequential technique about sketch style image generation and face area painting.

• Journal of Korea Game Society
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• v.8 no.1
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• pp.59-70
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• 2008

A game graphics, one of computer graphics, has grown rapidly and diversified expression techniques through continuous trials and studies. Rendering methods in game graphics are divided into two branches. The one is Protorealistic rendering method expressing realistic images like photos and the other is NPR(Non-Protorealistic rendering) method expressing emotion and artistry of human being. This paper analyzes how NPR techniques are used in game and what features are in their applications. And this paper suggests various effects for game graphics in an artistic viewpoint. So, this study aims at supporting production of more emotional, familiar and artistic games by understanding merits, demerits and applicabilities of recent NPR researches.

• Cartoon and Animation Studies
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• s.38
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• pp.133-144
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• 2015

Lighting work on 3D animation requires much time and labor. For example, about 60 lighting artists were needed for the theater animation named Postman Pat the Movie globally distributed in 2014. These artists were needed to rapidly respond with shot feedback. However, complicated shots required much of rendering time. Therefore, it was difficult to correspond the work in the middle of test rendering. After 2005, re-lighting techniques were developed to cope with such situations. However, it was not feasible to create shadow with current re-lighting technique which doesn't make natural or realistic result. This paper has realized relighting system that could realistic quality while maintaining fast calculation by applying rasterized ambient occlusion to the relighting calculation of each of the lights. This relighting system has been used for the Hollywood animation titled "Postman Pat: The Movie" globally released in 2014. It is anticipated for this method to be more widely used for animation manufacture that other manufacturers can reduce expenses and create well completed output in the future.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.2
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• pp.84-93
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• 2008

Modeling and rendering of cloth texture have been regarded as one of the most important factors to enhance reality of the contents in the digital contents industry. So far, however, two major approaches to realistically describe the cloth texture were developed: building analytical reflectance model for target cloth and sometimes thread itself and obtaining overall reflectance model using optical equipments. However, yielding a plausible analytic reflection model satisfying many subtle characteristics of a cloth is not an easy task; moreover, fine-detailed modeling of the cloth pattern across the target clothes should also be accompanied by huge amount of computation. The method to obtain overall reflectance model needs expensive measurement equipments and data size becomes huge. Since it applies in the end the reflectance model obtained at one point of a cloth to across whole the visible area of the target clothes, it cannot properly reproduce the pattern of the clothes nor the texture. To address the aforementioned problems, this paper proposes a simple low cost camera rig and a novel method for realistic modeling and rendering of the cloth texture by analyzing photos taken by the proposed camera rig, which can reproduce even the texture pattern applied to the whole clothes, overcoming the one-point reflectance model.

• Journal of Korea Game Society
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• v.3 no.2
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• pp.30-34
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• 2003

Image-based rendering is an approach to generate realistic images in real-time without modeling explicit 3D geometry, Especially, TIP(Tour Into the Picture) is preferred for its simplicity in constructing 3D background scene. However, TP has a limitation that a viewpoint cannot go far from the origin of the TIP for the lack of geometrical information. in this paper, we propose a method to interpolating the TIP images to generate smooth and realistic navigation. We construct multiple TIP models in a wide area of the virtual environment. Then we interpolate foreground objects and background object respectively to generate smooth navigation results.