A Temporal Coherence Based Framework for Visualizing Time-Varying Unstructured Volume with PBVR

Time-varying visualization is always an important topic in the field of scientific visualization. Due to the large data size and complex grid, the unstructured time-varyingvisualization is still a hard problem. In this paper, we propose atemporal coherence based framework for visualizing large-scale time-varying unstructured volumewith the Particle-based volume rendering (PBVR).PBVR is a visibility sorting free rendering method, which can render a large-scale unstructured grid dataset efficiently. However, the pre-process of PBVR, which is to generate particles from the original volume, can always cost too much time. To overcome this problem, we utilize the temporal coherence between consecutive time steps to decrease the particle generation time.After the particle generation, we also compress the particle data before it is stored in hard disk. In account of the compressed data size, the loading time of the particle data during the rendering process is decreased obviously.And after the loading of the particle data, our system can render the data as an animation very smoothly by utilizing the LOD control of PBVR.We applied our system to rendering of 465 time steps of 3,676,828 hexahedral cell grid dataset to confirm the effectiveness.