• ETRI Journal
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• v.36 no.6
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• pp.1008-1015
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• 2014

In this paper, we present a method for reconstructing a surface mesh animation sequence from point cloud animation data. We mainly focus on the articulated body of a subject - the motion of which can be roughly described by its internal skeletal structure. The point cloud data is assumed to be captured independently without any inter-frame correspondence information. Using a template model that resembles the given subject, our basic idea for reconstructing the mesh animation is to deform the template model to fit to the point cloud (on a frame-by-frame basis) while maintaining inter-frame coherence. We first estimate the skeletal motion from the point cloud data. After applying the skeletal motion to the template surface, we refine it to fit to the point cloud data. We demonstrate the viability of the method by applying it to reconstruct a fast dancing motion.

• ETRI Journal
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• v.28 no.6
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• pp.697-708
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• 2006

Various adaptive mesh refinement techniques are often employed in numerical simulations for increasing spatial and temporal resolution beyond the limits imposed by available CPU time and memory space. Recently, an octree-based adaptive mesh structure was successfully used in fluid animation to place more grid cells efficiently in visually interesting regions of fluids. In an attempt to optimize the use of computational resources further in fluid animation, this paper extends this adaptive technique by modifying the mesh refinement scheme so that the camera's viewing properties are dynamically exploited during the simulation. Based on a simple adaptive mesh structure, we show that the new meshing strategy can save a substantial amount of computation time and memory space by using a view-dependent adaptive approach. The experimental results reveal that the proposed technique provides a good compromise between the computational effort and the simulation's fidelity, and may be used quite effectively in 3D animation production.

• Journal of Korea Game Society
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• v.9 no.4
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• pp.97-106
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• 2009

In this paper, a realtime approach to the simulation of virtual paper with an adaptive mesh structure is proposed. The proposed method can be applied to arbitrary triangular mesh structures and efficiently produces wrinkles and creases on the paper surface with stable numerical integration and deformation-based mesh refinement. In order to plausibly represent the crumples on the paper object, we employed an adaptive mesh structure with breakable springs. Because the adaptive structure continuously inserts or removes vertices and edges to or from the mesh structure, the conservation of the mass and the momentum should be carefully taken into account for the plausible simulation of the virtual paper. The proposed method produced plausible animation of paper-like thin shell in realtime environments.

• The Journal of the Korea Contents Association
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• v.14 no.8
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• pp.13-21
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• 2014

The paper provides an efficient method for generating water crown animation. Compared to general liquid simulation, water crown animation requires tremendous computational loads. Tackling the problem, we propose a novel geometry based approach with procedural texture. Unreal engine is utilized to construct material and handle the geometric mesh combined with water texture. The experimental results demonstrate our method achieves effective performance for realistic water crown animation.

• Journal of Korea Game Society
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• v.8 no.2
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• pp.47-55
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• 2008

This paper introduces that SSFE(Skeleton System for Facial Expression) to deform facial expressions by rigging of skeletons does same functions with 14 facial muscles based on anatomy. A three dimensional animation tool (MAYA 8.5) is utilized for making the SSFE that presents deformation of mesh models implementing facial expressions around eyes, nose and mouse. The SSFE has a good reusability within diverse human mesh models. The reusability of SSFE can be understood as OSMU(One Source Multi Use) of three dimensional animation production method. It can be a good alternative technique for reducing production budget of animations. It can also be used for three dimensional animation industries such as virtual reality and game.

• Journal of the Korea Society of Computer and Information
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• v.16 no.10
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• pp.93-100
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• 2011

The necessity of research on extracting information of face and facial components in animation characters have been increasing since they can effectively express the emotion and personality of characters. In this paper, we introduce a method to extract face and facial components of animation characters by defining a mesh model adequate for characters and by using dominant colors. The suggested algorithm first generates a mesh model for animation characters, and extracts dominant colors for face and facial components by adapting the mesh model to the face of a model character. Then, using the dominant colors, we extract candidate areas of the face and facial components from input images and verify if the extracted areas are real face or facial components by means of color similarity measure. The experimental results show that our method can reliably detect face and facial components of animation characters.

• The Journal of the Korea Contents Association
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• v.3 no.4
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• pp.69-76
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• 2003

Recently, in computer graphics, researches on 3D animations have been very active. one of the important research areas in 3D animation is animation of human being. The creation and animation of 3D facial models has depended on animators' manual work frame by frame. Thus, it needs many efforts and time as well as various hardwares and softwares. In this paper, we implements a way to generation 3D human face model easily and quickly just with the front face images. Then, we suggests a methodology for mesh data simplification of 3D generic model.

• The Journal of the Korea Contents Association
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• v.9 no.5
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• pp.76-83
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• 2009

This paper presents a compression method for animated meshes or mesh sequences which have a shared connectivity and geometry streams. Our approach is based on static semi-regular mesh compression algorithm introduced by Khodakovky et al. Our encoding algorithm consists of two stages. First, the proposed technique creates a semi-regular mesh sequence from an input irregular mesh sequence. For semi-regular remeshing of irregular mesh sequences, this paper adapts the MAPS algorithm. However, MAPS cannot directly be performed to the input irregular mesh sequence. Thus, the proposed remesh algorithm revises the MAPS remesher using the clustering information, which classify coherent parts during the animation. The second stage uses wavelet transformation and clustering information to compress geometries of mesh sequences efficiently. The proposed compression algorithm predicts the vertex trajectories using the clustering information and the cluster transformation during the animation and compress the difference other frames from the reference frame in order to reduce the range of 3D position values.

• Journal of Computational Design and Engineering
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• v.3 no.2
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• pp.121-131
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• 2016

Organic modeling of 3D characters is a challenging task when it comes to correctly modeling the anatomy of the human body. Most sketch based modeling tools available today for modeling organic models (humans, animals, creatures etc) are focused towards modeling base mesh models only and provide little or no support to add details to the base mesh. We propose a hybrid approach which combines geometrical primitives such as generalized cylinders and cube with Shape-from-Shading (SFS) algorithms to create plausible human character models from sketches. The results show that an artist can quickly create detailed character models from sketches by using this hybrid approach.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.10
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• pp.759-767
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• 2006

The level-of-detail (LoD), which is a method of reducing polygons on mesh, is one of the most fundamental techniques in real-time rendering. In this paper, we propose a novel level-of-detail technique applied to the virtual character's motion (Motion LoD). The movement of a virtual character can be defined as the transformation of each joint and it's relation to the mesh. The basic idea of the proposed 'Motion LoD' method is to reduce number of joints in an articulated figure and minimize the error between original and simplified motion. For the motion optimization, we propose an error estimation method and a linear system reconstructed from this error estimation for a fast optimization. The proposed motion simplification method is effectively useful for motion editing and real-time crowd animation.