Based upon motion capture,a semi-automatic technique for fast facial animation was implemented. While capturing the facial expressions from a performer,a camera was used to record her /his front face as a texture map....Based upon motion capture,a semi-automatic technique for fast facial animation was implemented. While capturing the facial expressions from a performer,a camera was used to record her /his front face as a texture map. The radial basis function( RBF) technique was utilized to deform a generic facial model and the texture was remapped to generate a personalized face.Partitioning the personalized face into three regions and using the captured facial expression data,the RBF and Laplacian operator,and mean-value coordinates were implemented to deform each region respectively. With shape blending,the three regions were combined together to construct the final face model. Our results show that the technique is efficient in generating realistic facial animation.展开更多
An important contribution of action in animation comes from secondary motion.We apply the technique of secondary motion into animation to refer to passive motions,which are generated in response to the movements of ch...An important contribution of action in animation comes from secondary motion.We apply the technique of secondary motion into animation to refer to passive motions,which are generated in response to the movements of character and objects in the scene or any environmental forces.This paper aims to introduce the application of secondary action in animation.An animation of walk from my own projects is introduced as an example,and human body Falling down is used to compare and contrast the different actions involved in secondary motions.展开更多
Animals have evolved a variety of behavior patterns to adapt to the environment. Motion-capture technology is utilized to quantify and characterize locomotor behaviors to reveal the mechanisms of animal motion. In the...Animals have evolved a variety of behavior patterns to adapt to the environment. Motion-capture technology is utilized to quantify and characterize locomotor behaviors to reveal the mechanisms of animal motion. In the capture of flexible, small animals with complex locomotor behaviors, the markers interfere with each other easily, and the motion forms(bending, twisting) of the moving parts are obviously different;thus, it is a great challenge to realize accurate quantitative characterization of complex locomotor behaviors. The correlation between the marker properties, including the size and space length, and the precision of the system are revealed in this paper, and the effects of diverse marker shapes on the capturing accuracy of the captured objects in different motion forms were tested. Results showed that the precision of system is significantly improved when the ratio of the space length to the diameter of the markers is larger than four;for the capture of the spatial twisting motion of the flexible object, the hexagon markers had the lowest spatial lost-marker rate relative to the circle, triangle, and square. Customized markers were used to capture the locomotor behavior of the gecko-inspired robot(rigid connection) and the gecko(flexible connection). The results showed that this marking technology can achieve high accuracy of motion capture for geckos(the average deviation was approximately 0.32 mm, and the average deviation’s variation rate was approximately 0.96%). In this paper, the marking technology for the motion capture of flexible, small animals with complex motion is proposed;it can effectively improve the system precision as well as the capture accuracy, and realize the quantitative characterization of the complex motion of flexible, small objects. It provides a reliable technical means to deeply study the evolution of the motion function of small animals and advance systematic research of motion-capture technology.展开更多
Background Synthesizing dance motions to match musical inputs is a significant challenge in animation research.Compared to functional human motions,such as locomotion,dance motions are creative and artistic,often infl...Background Synthesizing dance motions to match musical inputs is a significant challenge in animation research.Compared to functional human motions,such as locomotion,dance motions are creative and artistic,often influenced by music,and can be independent body language expressions.Dance choreography requires motion content to follow a general dance genre,whereas dance performances under musical influence are infused with diverse impromptu motion styles.Considering the high expressiveness and variations in space and time,providing accessible and effective user control for tuning dance motion styles remains an open problem.Methods In this study,we present a hierarchical framework that decouples the dance synthesis task into independent modules.We use a high-level choreography module built as a Transformer-based sequence model to predict the long-term structure of a dance genre and a low-level realization module that implements dance stylization and synchronization to match the musical input or user preferences.This novel framework allows the individual modules to be trained separately.Because of the decoupling,dance composition can fully utilize existing high-quality dance datasets that do not have musical accompaniments,and the dance implementation can conveniently incorporate user controls and edit motions through a decoder network.Each module is replaceable at runtime,which adds flexibility to the synthesis of dance sequences.Results Synthesized results demonstrate that our framework generates high-quality diverse dance motions that are well adapted to varying musical conditions and user controls.展开更多
Recently, there has been considerable effort to bring together quaternion-based representations of spatial displacements with curve design techniques in Computer Aided Geometric Design (CAGD) to develop methods for sy...Recently, there has been considerable effort to bring together quaternion-based representations of spatial displacements with curve design techniques in Computer Aided Geometric Design (CAGD) to develop methods for synthesizing freeform Cartesian motions. These methods have a wide range of applications from computer graphics,Cartesian motion planning for robot manipulators to task specification and motion approximation for spatial mechanism design. This paper compares the use of quaternions, dual quaternions, and double quaternions for freeform motion synthesis in a CAD environment.展开更多
The purpose of this research is a quantitative analysis of movement patterns of dance, which cannot be analyzed with a motion capture system alone, using simultaneous measurement of body motion and biophysical informa...The purpose of this research is a quantitative analysis of movement patterns of dance, which cannot be analyzed with a motion capture system alone, using simultaneous measurement of body motion and biophysical information. In this research, two kinds of same leg movement are captured by simultaneous measurement; one is a leg movement with given strength, the other is a leg movement without strength on condition of basic experiment using optical motion capture and electromyography （EMG） equipment in order to quantitatively analyze characteristics of leg movement. Also, we measured the motion of the traditional Japanese dance using the constructed system. We can visualize leg movement of Japanese dance by displaying a 3D CG character animation with motion data and EMG data. In addition, we expect that our research will help dancers and researchers on dance through giving new information on dance movement which cannot be analyzed with only motion capture.展开更多
As commercial motion capture systems are widely used, more and more 3D motion libraries become available, reinforcing the demand for efficient indexing and retrieving methods. Usually, the user will only have a sketch...As commercial motion capture systems are widely used, more and more 3D motion libraries become available, reinforcing the demand for efficient indexing and retrieving methods. Usually, the user will only have a sketchy idea of which kind of motion to look for in the motion database. As a result, how to clearly describe the user’s demands is a bottleneck for motion retrieval system. This paper presented a framework that can handle this problem effectively for motion retrieval. This content-based retrieval system supports two kinds of query modes: textual query mode and query-by-example mode. In both query modes, user’s input is translated into scene description language first, which can be processed by the system efficiently. By using various kinds of qualitative features and adaptive segments of motion capture data stream, indexing and retrieval methods are carried out at the segment level rather than at the frame level, making them quite efficient. Some experimental examples are given to demonstrate the effectiveness and efficiency of the proposed algorithms.展开更多
In this paper, a novel motion texture approach is presented for synthesizing long character motion (e.g., kungfu) that is similar to the original short input motion. First, a new motion with repeated frames is generat...In this paper, a novel motion texture approach is presented for synthesizing long character motion (e.g., kungfu) that is similar to the original short input motion. First, a new motion with repeated frames is generated by exploiting the symmetric properties of the frames and reversing the motion sequence playback in a given motion sequence. Then, the order of the above motion sequence is rearranged by putting the start and the end frames together. The graphcut algorithm is used to seamlessly synthesize the transition between the start and the end frames, which is noted as graphcut-based motion-texton. Finally, we utilize the motion-textons to synthesize long motion texture, which can be patched together like the image texture synthesis method using graphcut algorithm, and automatically form a long motion texture endlessly. Our approach is demonstrated by synthesizing the long kungfu motion texture without visual artifacts, together with post-processing including our new developed graphcut-based motion blending and Poisson-based motion smoothing techniques.展开更多
A new motion retargeting algorithm is presented, which adapts me motion capture data to a new character. To make the resulting motion realistic, the physically-based optimization method is adopted. However, the optimi...A new motion retargeting algorithm is presented, which adapts me motion capture data to a new character. To make the resulting motion realistic, the physically-based optimization method is adopted. However, the optimization process is difficult to converge to the optimal value because of high complexity of the physical human model. In order to address this problem, an appropriate simplified model automatically determined by a motion analysis technique is utilized, and then motion retargeting with this simplified model as an intermediate agent is implemented. The entire motion retargeting algorithm involves three steps of nonlinearly constrained optimization： forward retargeting, motion scaling and inverse retargeting. Experimental results show the validity of this algorithm.展开更多
Femoral head necrosis has become one of the common and difficult diseases of orthopedics,and its incidence is now on a clear upward trend.If the effective treatment is not carried out in the early stage,it will lead t...Femoral head necrosis has become one of the common and difficult diseases of orthopedics,and its incidence is now on a clear upward trend.If the effective treatment is not carried out in the early stage,it will lead to the collapse of local necrotic bone,which will seriously endanger human health and even cause it to lose its ability to work and self-care,and eventually cause disability.Its treatment program has not made great breakthroughs at home and abroad.However,an animal model that fully reflects human osteonecrosis has not yet been fully replicated.Therefore,it is necessary to establish an animal model that can conform to the pathological evolution process of avascular necrosis of human femoral head.It is necessary to study the preparation of liquid nitrogen-type ONFH model by reviewing relevant literatures at home and abroad in recent years.展开更多
Silk Road dance is an excellent traditional Chinese dance drama, which has high artistic values. This article introduces the virtual performance techniques of Silk Road based on motion capture. First, obtain the dance...Silk Road dance is an excellent traditional Chinese dance drama, which has high artistic values. This article introduces the virtual performance techniques of Silk Road based on motion capture. First, obtain the dance data using motion capture technique according to the features of dance itself, then establish figure model, finally combines these data to make 3-D animation system to perform Silk Road, meanwhile designs some interfaces to introduce it. This system excavates details of the dance, and can be reference of man-machine interaction and animation production.展开更多
基金Youth Foundation of Higher Education Scientific Research of Hebei Province,China(No.2010228)Foundation for Returned Overseas Scholars of Hebei Province,China(No.C2013003015)
文摘Based upon motion capture,a semi-automatic technique for fast facial animation was implemented. While capturing the facial expressions from a performer,a camera was used to record her /his front face as a texture map. The radial basis function( RBF) technique was utilized to deform a generic facial model and the texture was remapped to generate a personalized face.Partitioning the personalized face into three regions and using the captured facial expression data,the RBF and Laplacian operator,and mean-value coordinates were implemented to deform each region respectively. With shape blending,the three regions were combined together to construct the final face model. Our results show that the technique is efficient in generating realistic facial animation.
文摘An important contribution of action in animation comes from secondary motion.We apply the technique of secondary motion into animation to refer to passive motions,which are generated in response to the movements of character and objects in the scene or any environmental forces.This paper aims to introduce the application of secondary action in animation.An animation of walk from my own projects is introduced as an example,and human body Falling down is used to compare and contrast the different actions involved in secondary motions.
基金funded by the National Natural Science Foundation of China (Grant Nos. 31601870 and 51435008)Natural Science Foundation of Jiangsu Province, China (Grant No. SBK20160800 to Zhouyi WANG)Jiangsu Provincial Key Laboratory of Bionic Functional Materials
文摘Animals have evolved a variety of behavior patterns to adapt to the environment. Motion-capture technology is utilized to quantify and characterize locomotor behaviors to reveal the mechanisms of animal motion. In the capture of flexible, small animals with complex locomotor behaviors, the markers interfere with each other easily, and the motion forms(bending, twisting) of the moving parts are obviously different;thus, it is a great challenge to realize accurate quantitative characterization of complex locomotor behaviors. The correlation between the marker properties, including the size and space length, and the precision of the system are revealed in this paper, and the effects of diverse marker shapes on the capturing accuracy of the captured objects in different motion forms were tested. Results showed that the precision of system is significantly improved when the ratio of the space length to the diameter of the markers is larger than four;for the capture of the spatial twisting motion of the flexible object, the hexagon markers had the lowest spatial lost-marker rate relative to the circle, triangle, and square. Customized markers were used to capture the locomotor behavior of the gecko-inspired robot(rigid connection) and the gecko(flexible connection). The results showed that this marking technology can achieve high accuracy of motion capture for geckos(the average deviation was approximately 0.32 mm, and the average deviation’s variation rate was approximately 0.96%). In this paper, the marking technology for the motion capture of flexible, small animals with complex motion is proposed;it can effectively improve the system precision as well as the capture accuracy, and realize the quantitative characterization of the complex motion of flexible, small objects. It provides a reliable technical means to deeply study the evolution of the motion function of small animals and advance systematic research of motion-capture technology.
基金Supported by Startup Fund 20019495,McMaster University。
文摘Background Synthesizing dance motions to match musical inputs is a significant challenge in animation research.Compared to functional human motions,such as locomotion,dance motions are creative and artistic,often influenced by music,and can be independent body language expressions.Dance choreography requires motion content to follow a general dance genre,whereas dance performances under musical influence are infused with diverse impromptu motion styles.Considering the high expressiveness and variations in space and time,providing accessible and effective user control for tuning dance motion styles remains an open problem.Methods In this study,we present a hierarchical framework that decouples the dance synthesis task into independent modules.We use a high-level choreography module built as a Transformer-based sequence model to predict the long-term structure of a dance genre and a low-level realization module that implements dance stylization and synchronization to match the musical input or user preferences.This novel framework allows the individual modules to be trained separately.Because of the decoupling,dance composition can fully utilize existing high-quality dance datasets that do not have musical accompaniments,and the dance implementation can conveniently incorporate user controls and edit motions through a decoder network.Each module is replaceable at runtime,which adds flexibility to the synthesis of dance sequences.Results Synthesized results demonstrate that our framework generates high-quality diverse dance motions that are well adapted to varying musical conditions and user controls.
文摘Recently, there has been considerable effort to bring together quaternion-based representations of spatial displacements with curve design techniques in Computer Aided Geometric Design (CAGD) to develop methods for synthesizing freeform Cartesian motions. These methods have a wide range of applications from computer graphics,Cartesian motion planning for robot manipulators to task specification and motion approximation for spatial mechanism design. This paper compares the use of quaternions, dual quaternions, and double quaternions for freeform motion synthesis in a CAD environment.
基金This work was partly supported by the"21st Century COE program",the"Open Research Center program"the"Grantin-in-Aid for Scientific Research"of the Ministry of Education,Science,Sports and Culture(No.(B)16300035).
文摘The purpose of this research is a quantitative analysis of movement patterns of dance, which cannot be analyzed with a motion capture system alone, using simultaneous measurement of body motion and biophysical information. In this research, two kinds of same leg movement are captured by simultaneous measurement; one is a leg movement with given strength, the other is a leg movement without strength on condition of basic experiment using optical motion capture and electromyography （EMG） equipment in order to quantitatively analyze characteristics of leg movement. Also, we measured the motion of the traditional Japanese dance using the constructed system. We can visualize leg movement of Japanese dance by displaying a 3D CG character animation with motion data and EMG data. In addition, we expect that our research will help dancers and researchers on dance through giving new information on dance movement which cannot be analyzed with only motion capture.
基金National Natural Science Foundation of Chi-na (No. 60573147, No. 60373070) Mi-crosoft Research Asia (Project-2004-Image-01)
文摘As commercial motion capture systems are widely used, more and more 3D motion libraries become available, reinforcing the demand for efficient indexing and retrieving methods. Usually, the user will only have a sketchy idea of which kind of motion to look for in the motion database. As a result, how to clearly describe the user’s demands is a bottleneck for motion retrieval system. This paper presented a framework that can handle this problem effectively for motion retrieval. This content-based retrieval system supports two kinds of query modes: textual query mode and query-by-example mode. In both query modes, user’s input is translated into scene description language first, which can be processed by the system efficiently. By using various kinds of qualitative features and adaptive segments of motion capture data stream, indexing and retrieval methods are carried out at the segment level rather than at the frame level, making them quite efficient. Some experimental examples are given to demonstrate the effectiveness and efficiency of the proposed algorithms.
基金Project supported by the National Natural Science Foundation of China (Nos. 60573153 and 60533080), and Program for New Century Excellent Talents in University (No. NCET-05-0519), China
文摘In this paper, a novel motion texture approach is presented for synthesizing long character motion (e.g., kungfu) that is similar to the original short input motion. First, a new motion with repeated frames is generated by exploiting the symmetric properties of the frames and reversing the motion sequence playback in a given motion sequence. Then, the order of the above motion sequence is rearranged by putting the start and the end frames together. The graphcut algorithm is used to seamlessly synthesize the transition between the start and the end frames, which is noted as graphcut-based motion-texton. Finally, we utilize the motion-textons to synthesize long motion texture, which can be patched together like the image texture synthesis method using graphcut algorithm, and automatically form a long motion texture endlessly. Our approach is demonstrated by synthesizing the long kungfu motion texture without visual artifacts, together with post-processing including our new developed graphcut-based motion blending and Poisson-based motion smoothing techniques.
文摘A new motion retargeting algorithm is presented, which adapts me motion capture data to a new character. To make the resulting motion realistic, the physically-based optimization method is adopted. However, the optimization process is difficult to converge to the optimal value because of high complexity of the physical human model. In order to address this problem, an appropriate simplified model automatically determined by a motion analysis technique is utilized, and then motion retargeting with this simplified model as an intermediate agent is implemented. The entire motion retargeting algorithm involves three steps of nonlinearly constrained optimization： forward retargeting, motion scaling and inverse retargeting. Experimental results show the validity of this algorithm.
基金Shenyang Bureau of Science and Technology(18-014-4-05).
文摘Femoral head necrosis has become one of the common and difficult diseases of orthopedics,and its incidence is now on a clear upward trend.If the effective treatment is not carried out in the early stage,it will lead to the collapse of local necrotic bone,which will seriously endanger human health and even cause it to lose its ability to work and self-care,and eventually cause disability.Its treatment program has not made great breakthroughs at home and abroad.However,an animal model that fully reflects human osteonecrosis has not yet been fully replicated.Therefore,it is necessary to establish an animal model that can conform to the pathological evolution process of avascular necrosis of human femoral head.It is necessary to study the preparation of liquid nitrogen-type ONFH model by reviewing relevant literatures at home and abroad in recent years.
基金Co-supported by Gansu Science and Technology Major Project(1302FKDA036)Natural Science Fund Project in Xinjiang(2014211A046)
文摘Silk Road dance is an excellent traditional Chinese dance drama, which has high artistic values. This article introduces the virtual performance techniques of Silk Road based on motion capture. First, obtain the dance data using motion capture technique according to the features of dance itself, then establish figure model, finally combines these data to make 3-D animation system to perform Silk Road, meanwhile designs some interfaces to introduce it. This system excavates details of the dance, and can be reference of man-machine interaction and animation production.
