• Journal of the Korea Computer Graphics Society
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• v.26 no.2
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• pp.11-19
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• 2020

When a character's pose changes, its center of mass(COM) also changes. The change of COM has distinctive patterns corresponding to various motion types like walking, running or sitting. Thus the motion type can be predicted by using COM movement. We propose a motion generator that uses character's center of mass information. This generator can generate various motions without annotated action type labels. Thus dataset for training and running can be generated full-automatically. Our neural network model takes the motion history of the character and its center of mass information as inputs and generates a full-body pose for the current frame, and is trained using simple Convolutional Neural Network(CNN) that performs 1D convolution to deal with time-series motion data.

• Journal of the Korea Society of Computer and Information
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• v.27 no.8
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• pp.85-90
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• 2022

In this study, to reduce the time and cost disadvantages of the traditional motion graphic production method in order to realize the movement of a virtual camera identical to that of the real camera, motion graphics virtualization using AR Core-based mobile device real-time tracking data A method for creating a camera is proposed. The proposed method is a method that simplifies the tracking operation in the video file stored after shooting, and simultaneously proceeds with shooting on an AR Core-based mobile device to determine whether or not tracking is successful in the shooting stage. As a result of the experiment, there was no difference in the motion graphic result image compared to the conventional method, but the time of 6 minutes and 10 seconds was consumed based on the 300frame image, whereas the proposed method has very high time efficiency because this step can be omitted. At a time when interest in image production using virtual augmented reality and various studies are underway, this study will be utilized in virtual camera creation and match moving.

• Journal of the Korea Computer Graphics Society
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• v.28 no.4
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• pp.13-22
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• 2022

In this paper, we propose a single framework based on the MPM(Material Point Method) that can represent the dynamic angular motion of the elementary particle unit. In this study, the particles can have various shapes while also describing linear and angular motion. As a result, unlike other particle-based simulations, which only represent linear movements of spherical (e.g. Circle, Sphere) particles, it is possible to express the visually dynamic motion of them. The proposed framework utilizes MPM, due to the fact that rotational motion can be decomposed and derived from large deformation. During the integration process of the presented technique, a deformation gradient tensor is decomposed by polar decomposition theory for extracting rotation tensor. By applying this together with the linear motion of each particle, as a result, it is possible to simultaneously express the angluar and linear motion of the particle itself. To verify the proposed method, we show the simulation of rotating particles scattering in the wind field, and the interaction(e.g. Collision) between a moving object and them by comparing the traditional MPM

• Journal of Korea Multimedia Society
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• v.23 no.2
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• pp.361-367
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• 2020

This study analyzed the factors consisting moving poster design. In order to analyze the elements of moving poster, the researcher reorganized the elements of moving posters by referring to the previous studies on printed posters, motion graphics and works of moving posters. In this study, moving poster components were classified into 'communication', 'visual and form', and 'sound'. In 'communication' section, moving posters had narrative elements, including scenes, because of the time and movement added by the poster's original function. The 'visual and form' section was classified into graphics, layouts, movement, and time. Graphics refered to various graphic objects constituting the screen such as photo, illustration, typography, color, diagram. Layout means screen layout, size, and orientation of the screen. Movement section was divided into 'subject of movement' and 'attributes of movement'. Time was classified physical time such as playing time and subjective time felt by the audience. Also, the researcher categorized 'sound' as an additional section, since most moving posters did not include sound.

• Journal of the Korea Society of Computer and Information
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• v.24 no.4
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• pp.19-26
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• 2019

In this study, we study the development and control of motion of 3D character animation and discuss the development direction of technology. Character animation has been developed as a data-based method and a physics-based method. The animation generation technique based on the keyframe method has been made possible by the development of the hardware technology, and the motion capture device has been used. Various techniques for effectively editing the motion data have appeared. At the same time, animation techniques based on physics have emerged, which realistically generate the motion of the character by physically optimized numerical computation. Recently, animation techniques using machine learning have shown new possibilities for creating characters that can be controlled by the user in real time and are expected to be developed in the future.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.10
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• pp.796-800
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• 2009

Currently, there are many software tools that can generate 3D human figure models and animations based on the advancement of computer graphics technology. However, we still have problems in interoperability of human data models in different applications because common data models do not exist. To address this issue, the Web3D Consortium and the ISO/IEC JTC1 SC24 WG6 have developed the H-Anim standard. However, H-Anim does not include human motion data formats although it defines the structure of a human figure. This research is intended to obtain interoperable human animation by defining the data for human motions in H- Anim figures. In this paper, we describe a syntactic method to define motion data for the H-Anim figure and its implementation. In addition, we describe a method of specifying motion parameters necessary for generating animations by using an arbitrary character model data set created by a general graphics tool.

• Journal of the Korea Computer Graphics Society
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• v.13 no.4
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• pp.29-36
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• 2007

The objective of this paper is to develop the motion recognition method for the rehabilitation program of the people with physical disabilities. Using the infrared ray LED, this method gets the information of the user's motion and tells the difference between the information we get and the pre-defined information. In order to get the fast recognition and comparison, this method positions the specific coordinates of infrared ray LED in the pre-classified sector which keeps certain distance and angle from the point of origin. The result in our experiment shows the speed over 20 frames per second in every motion, and we are satisfied the rate for the recognition of the motions which is near 98%.

• Journal of the Korea Computer Graphics Society
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• v.25 no.3
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• pp.133-142
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• 2019

In physics-based character animation, trajectory optimization has been widely adopted for automatic motion synthesis, through the prediction of an optimal sequence of future states of the character based on its system dynamics model. In general, the system dynamics model is neither in a closed form nor differentiable when it handles the contact dynamics between a character and the environment with rigid body collisions. Employing smoothed contact dynamics, researchers have suggested efficient trajectory optimization techniques based on numerical differentiation of the resulting system dynamics. However, the numerical derivative of the system dynamics model could be inaccurate unlike its analytical counterpart, which may affect the stability of trajectory optimization. In this paper, we propose a novel method to derive the closed-form derivative for the system dynamics by properly approximating the contact model. Based on the resulting derivatives of the system dynamics model, we also present a model predictive control (MPC)-based motion synthesis framework to robustly control the motion of a biped character according to on-line user input without any example motion data.

• Journal of the Korea Computer Graphics Society
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• v.29 no.4
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• pp.7-16
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• 2023

For decades, creating a desired locomotive motion in a goal-oriented manner has been a challenge in character animation. Data-driven methods using generative models have demonstrated efficient ways of predicting long sequences of motions without the need for explicit conditioning. While these methods produce high-quality long-term motions, they can be limited when it comes to synthesizing motion for challenging novel scenarios, such as punching a random target. A state-of-the-art solution to overcome this limitation is by using a GAN Discriminator to imitate motion data clips and incorporating reinforcement learning to compose goal-oriented motions. In this paper, our research aims to create characters performing combat sports such as boxing, using a novel reward design in conjunction with existing GAN-based approaches. We experimentally demonstrate that both the Adversarial Motion Prior [3] and Adversarial Skill Embeddings [4] methods are capable of generating viable motions for a character punching a random target, even in the absence of mocap data that specifically captures the transition between punching and locomotion. Also, with a single learned policy, multiple task controllers can be constructed through the TimeChamber framework.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1415-1418
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• 2003

Recent performance improvement in computer and graphics hardware makes it possible to simulate a physical phenomenon in real time. VR department at ETRI has implemented a fast and robust physically based motion engine (PBM) for their general-purpose 3D online game engine. 'Dream 3D'. This paper shows the underlying algorithms of the PBM and introduces the structure and implementation results of it briefly.