The problems of the earth's gravity fields' visualization are both focus and puzzle currently. Aiming at multiresolution rendering, modeling of the Earth's gravity fields' data is discussed in the pape...The problems of the earth's gravity fields' visualization are both focus and puzzle currently. Aiming at multiresolution rendering, modeling of the Earth's gravity fields' data is discussed in the paper by using LOD algorithm based on Quad Tree. First, this paper employed the method of LOD based on Quad Tree to divide up the regional gravity anomaly data, introduced the combined node evaluation system that was composed of viewpoint related and roughness related systems, and then eliminated the T-cracks that appeared among the gravity anomaly data grids with different resolutions. The test results demonstrated that the gravity anomaly data grids' rendering effects were living, and the computational power was low. Therefore, the proposed algorithm was a suitable method for modeling the gravity anomaly data and has potential applications in visualization of the earth's gravity fields.展开更多
While most mesh streaming techniques focus on optimizing the transmission order of the polygon data, few approaches have addressed the streaming problems by using geometry images （GIM）. In this paper, we present a n...While most mesh streaming techniques focus on optimizing the transmission order of the polygon data, few approaches have addressed the streaming problems by using geometry images （GIM）. In this paper, we present a new approach which firstly partitions a mesh into several surface patches, then converts these patches into multi-chart geometry images （MCGIM）. After resampling the MCGIM and normal map atlas are obtained, we hierarchically construct the regular geometry image representation by adopting the quadtree structure. In this way, the encoded nodes can be transmitted in arbitrary order with high transmission flexibility. Also, the rendering quality of the partially transmitted models can be greatly improved by using the normal texture atlas. Meanwhile only the geometry on the silhouette to the current viewpoint are required to be refined and transmitted, therefore the amount of data is minimized for transferring each frame. In particular, our approach also allows users to encode and transmit the mesh data via JPEG2000 technique. Therefore, our mesh streaming method is suitable for transmitting 3D animation models with use of Motion JPEG2000 videos. Experimental results have demonstrated the effectiveness of our approach, which enables one server to stream the MCGIM texture atlas to the clients. Also, the transmitted model can be rendered in a multiresolution manner by GPU acceleration on the client side, due to the regular geometry structure of MCGIM.展开更多
文摘The problems of the earth's gravity fields' visualization are both focus and puzzle currently. Aiming at multiresolution rendering, modeling of the Earth's gravity fields' data is discussed in the paper by using LOD algorithm based on Quad Tree. First, this paper employed the method of LOD based on Quad Tree to divide up the regional gravity anomaly data, introduced the combined node evaluation system that was composed of viewpoint related and roughness related systems, and then eliminated the T-cracks that appeared among the gravity anomaly data grids with different resolutions. The test results demonstrated that the gravity anomaly data grids' rendering effects were living, and the computational power was low. Therefore, the proposed algorithm was a suitable method for modeling the gravity anomaly data and has potential applications in visualization of the earth's gravity fields.
基金supported by the National Basic Research 973 Program of China under Grant No.2009CB320802the National Natural Science Foundation of China under Grant Nos.60473105,60773030RGC Research Grant(Ref.416007),RGC Direct Research Grant(No.2050349),and Grant of University of Macao
文摘While most mesh streaming techniques focus on optimizing the transmission order of the polygon data, few approaches have addressed the streaming problems by using geometry images （GIM）. In this paper, we present a new approach which firstly partitions a mesh into several surface patches, then converts these patches into multi-chart geometry images （MCGIM）. After resampling the MCGIM and normal map atlas are obtained, we hierarchically construct the regular geometry image representation by adopting the quadtree structure. In this way, the encoded nodes can be transmitted in arbitrary order with high transmission flexibility. Also, the rendering quality of the partially transmitted models can be greatly improved by using the normal texture atlas. Meanwhile only the geometry on the silhouette to the current viewpoint are required to be refined and transmitted, therefore the amount of data is minimized for transferring each frame. In particular, our approach also allows users to encode and transmit the mesh data via JPEG2000 technique. Therefore, our mesh streaming method is suitable for transmitting 3D animation models with use of Motion JPEG2000 videos. Experimental results have demonstrated the effectiveness of our approach, which enables one server to stream the MCGIM texture atlas to the clients. Also, the transmitted model can be rendered in a multiresolution manner by GPU acceleration on the client side, due to the regular geometry structure of MCGIM.
