Research On Optimization Of 3D Interactive Display For Out-of-core Seismic Volume On PC Platform

As an important research method,seismic visualization is widely used in geological exploration field with the development of visualization technology.However,the rapid growth in data size makes the real-time interactive visualization for seismic data on PC platform face great challenges.In order to solve the problem of the low interactive efficiency and the low rendering quality,several optimizations are proposed in this thesis.And the main work is as follows:(1)In the preprocessing stage of the original seismic data,in order to improve the accuracy of data processing,a specified sampling step and the "edge-fill" strategy is used to optimize the data extraction.The cumulative error caused by data interpolation is reduced and the rendering quality is improved after optimizing.In addition,by optimizing the extraction and scheduling of the volume blocks,the problem of "memory bottleneck" can be solved effectively.And the optimization maks it possible to support a larger scale of the original seismic during the data preprocessing.(2)Aiming at the problem of low rendering efficiency,a cache scheduling strategy is proposed,which schedules volume data from external storage to main memory and then to texture memory based on the measurement of spacial distance.And the proposed strategy ensures that the candidate blocks have a higher hit rate in the continuous interaction of multi slices.What's more,a prediction mechanism of blocks is designed to predict blocks that will be used in the next rendering according to the position and the moving direction of the slice.And the predicted blocks will be preloaded by child thread and it will improve the rendering efficiency.(3)In order to improve the rendering quality,frustum cull is used to improve the resolution of the effective blocks in frustum.In addition,information entropy is adopted to measure the user's interest area and the rendering quality is improved by promoting the resolution of the region of interest.What's more,in order to balance the contradiction between interactive efficiency and display quality,the two-stage rendering of real-time interaction and display optimization is proposed in this thesis.Experimental results indicate that the proposed methods can improve the overall cache hit rate effectively and the increase ratio is up to 60%.Meanwhile,the two-stage strategy can achieve higher quality images for application-oriented requirements and resolve the contradiction between the interaction efficiency and rendering quality for out-of-core seismic data visualization.