Ray casting algorithm can obtain a better quality image in volume rendering, however, it exists some problems, such as powerful computing capacity and slow rendering speed. How to improve the re-sampled speed is a key...Ray casting algorithm can obtain a better quality image in volume rendering, however, it exists some problems, such as powerful computing capacity and slow rendering speed. How to improve the re-sampled speed is a key to speed up the ray casting algorithm. An algorithm is introduced to reduce matrix computation by matrix transformation characteristics of re-sampling points in a two coordinate system. The projection of 3-D datasets on image plane is adopted to reduce the number of rays. Utilizing boundary box technique avoids the sampling in empty voxel. By extending the Bresenham algorithm to three dimensions, each re-sampling point is calculated. Experimental results show that a two to three-fold improvement in rendering speed using the optimized algorithm, and the similar image quality to traditional algorithm can be achieved. The optimized algorithm can produce the required quality images, thus reducing the total operations and speeding up the volume rendering.展开更多
In this paper,we present a novel ocean visualization framework,which focuses on analyzing multidimensional and spatiotemporal ocean data.GPU-based visualization methods are explored to effectively visualize ocean data...In this paper,we present a novel ocean visualization framework,which focuses on analyzing multidimensional and spatiotemporal ocean data.GPU-based visualization methods are explored to effectively visualize ocean data.An improved ray casting algorithm for heterogeneous multisection ocean volume data is presented.A two-layer spherical shell is taken as the ocean data proxy geometry,which enables oceanographers to obtain a real geographic background based on global terrain.An efficient ray sampling technique including an adaptive sampling technique and a preintegrated transfer function is proposed to achieve high-effectiveness and high-efficiency rendering.Moreover,an interactive transfer function is also designed to analyze the 3D structure of ocean temperature and salinity anomaly phenomena.Based on the framework,an integrated visualization system called i4Ocean is created.The visualization of ocean temperature and salinity anomalies extracted interactively by the transfer function is demonstrated.展开更多
文摘Ray casting algorithm can obtain a better quality image in volume rendering, however, it exists some problems, such as powerful computing capacity and slow rendering speed. How to improve the re-sampled speed is a key to speed up the ray casting algorithm. An algorithm is introduced to reduce matrix computation by matrix transformation characteristics of re-sampling points in a two coordinate system. The projection of 3-D datasets on image plane is adopted to reduce the number of rays. Utilizing boundary box technique avoids the sampling in empty voxel. By extending the Bresenham algorithm to three dimensions, each re-sampling point is calculated. Experimental results show that a two to three-fold improvement in rendering speed using the optimized algorithm, and the similar image quality to traditional algorithm can be achieved. The optimized algorithm can produce the required quality images, thus reducing the total operations and speeding up the volume rendering.
基金supported by the National Natural Science Foundation of China[grant number 42030406]the Marine Science&Technology Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)[grant number 2018SDKJ0102]+2 种基金the National Key R&D Program of China[grant number 2016YFC1401008]the ESA-NRSCC Scientific Cooperation Project on Earth Observation Science and Applications:Dragon 5[grant number 58393]the Open Fund of Key Laboratory of Urban Land Resources Monitoring and Simulation,Ministry of Natural Resources[grant number KF-2020-05-085].
文摘In this paper,we present a novel ocean visualization framework,which focuses on analyzing multidimensional and spatiotemporal ocean data.GPU-based visualization methods are explored to effectively visualize ocean data.An improved ray casting algorithm for heterogeneous multisection ocean volume data is presented.A two-layer spherical shell is taken as the ocean data proxy geometry,which enables oceanographers to obtain a real geographic background based on global terrain.An efficient ray sampling technique including an adaptive sampling technique and a preintegrated transfer function is proposed to achieve high-effectiveness and high-efficiency rendering.Moreover,an interactive transfer function is also designed to analyze the 3D structure of ocean temperature and salinity anomaly phenomena.Based on the framework,an integrated visualization system called i4Ocean is created.The visualization of ocean temperature and salinity anomalies extracted interactively by the transfer function is demonstrated.
