Research On Streamline Visualization Of Vector Data

Scientific computing visualization combines computer interaction,computer graphics,image processing and other related technologies.It involves scalar and vector field visualization,numerical simulation,flow field visualization,processing and transmission,massive data storage,parallel algorithms,graphics and image processing vectors,etc..Visualization technology is not only widely used in many basic disciplines such as physics,mathematics,mechanics,chemistry,and biology,but also applied to technical departments such as medicine,architecture,meteorology,geology,and manufacturing.Scientific computing visualization technology can allow scholars in various fields to analyze data more intuitively.This paper systematically introduces the related technology of vector field visualization,focusing on the part of streamline visualization technology in vector field visualization.The research is mainly focused on the extraction of topological structure of flow field,the algorithm of uniform placement of streamlines and the simplification of extraction of streamlines.For the uniform placement algorithm of streamlines,this paper combines the flow field topology to achieve.The topological structure of the flow field is the skeleton of the entire flow field and contains a lot of key information.The obtained topological structure of the flow field means that the key information of the flow field will not be ignored.Then place the streamlines evenly in each area to get a better visualization effect.For the simplified extraction of the flow field,this paper first classifies the flow lines according to the characteristics of the flow field,simplifies each category,and finally obtains the complete simplified flow field,which makes the visual expression clearer.The main work and innovations of this article are as follows:(1)Extraction and drawing of the topological structure of the flow field.According to the critical points in the flow field,the limit streamlines of the flow field are drawn to form the topological structure of the flow field,and the flow field is divided into several regions.(2)A streamline uniform placement algorithm based on flow field topology is proposed.The algorithm can accurately describe the key point information of the vector field,and then find a suitable seeding path to place the streamline evenly after obtaining the topological skeleton of the flow field.In this way,the key features of the flow field will not be missed,and the distribution of the streamlines is uniform,and there will be no large-scale blanks in the flow field.(3)In the process of flow field feature extraction,different methods are used to determine different feature streamlines.For the vortex streamlines,the improved winding angle method is used to determine.The determination of the source-sink point streamline is relatively simple.The source-sink point is the critical point of the velocity 0 in the flow field,so as to determine the source-sink point streamline.For the saddle point streamline,the method of information entropy is used to determine.(4)For the simplified process of the flow field,on the basis of judging the characteristic flow lines of the flow field,the different characteristic flow lines are divided into different categories,and then the similarity of the flow lines on each category is calculated,and finally according to the information entropy value The similarity value with the streamline simplifies the flow field and obtains a better visualization effect.Finally,we built a vector visualization plug-in and displayed the visualization effects on the plug-in.