Editorial Issue 27.6

Abstract

This issue contains four papers. In the first paper, Mingfei Wang, Jinyuan Jia, Ning Xie, and Chenxi Zhang, from Tongji University in Shanghai, China, aim to solve the challenging problems of choosing the data supplier for data-dispatching services in distributed virtual environments based on peer-to-peer networks. They propose a dynamic node-organizing mechanism that aims by applying the avatar's behavioral characteristics to the neighbor maintenance mechanism and scene data transmission. They have conducted extensive simulation experiments that simulate avatar behaviors in a popular online game. The results show that their proposed mechanism achieved a substantial alleviation of neighbor churn and reduced information exchange, which improves the transmission efficiency in DVEs. In the second paper, Masaki Oshita, from the Kyushu Institute of Technology, Japan, proposes an interactive character motion control interface that uses hands. Using their hands and fingers, the user can control a large number of degrees of freedom (DOFs) at the same time. The author applied principal component analysis (PCA) to a set of sample poses and assigned the extracted principal components to each DOF of the hands (such as the hand positions and finger bending/extending angles). The author developed methods for computing the feature vector, for applying PCA, and for pose and action synthesis. In addition, he introduced a pose transition method for performing a step motion when necessary to prevent foot sliding. He presents his experimental results and demonstrates the effectiveness of his interface. In the third paper, Wenwu Yang, Xun Wang, Wangbin Kou, Bailin Yang, and Guozheng Wang, from Zhejiang Gongshang University, Hangzhou, China, present a topology-aware method based on moving least squares (MLS) deformation approach for 2D characters. First, a Laplace equation is solved to obtain a set of weights, which are called as harmonic weights. Then, the MLS deformation is performed by using the harmonic weights as the deformation influence of the user-specified controls. Finally, the possible distortion in the traditional MLS deformation can be effectively avoided, since the harmonic weights spread the deformation of the controls in a localized and topology-aware way. In addition, a simple but effective area-preserving variant of MLS deformation is proposed, which is suitable for the editing of incompressible objects. Mohammadali Hajizadeh and Hossein Ebrahimnezhad, from Sahand University of Technology, Islamic Republic of Iran, propose a key frame-based technique for 3D dynamic mesh compression. First, key frames are extracted from the animated sequence. Extracted key frames are then linearly combined using blending weights to predict the vertex locations of the other frames. These blending weights play a key role in the proposed algorithm since the prediction performance and the required number of key frames are greatly dependent on these weights. They present a novel method in order to compute the optimum blending weight, which makes it possible to predict location of the vertices of the non-key frames with the minimum number of key frames. The residual prediction errors are finally quantized and encoded using Huffman coding and another heuristic method. Experimental results on different test sequences with various sizes, topologies, and geometries demonstrate the privileged performance of the proposed method compared to the previous techniques.