Research On Techniques Of Interactive Visualization For 3D Flow Field

With the acquisition of data becoming easier,how to deal with data becomes an important direction.The flow visualization mainly displays flow data intuitively with computer graphics and it can help users explore and find information in the flow.In the field visualization,the interactive method can show the results according to the user's needs.However,there are still some problems in the interactive methods.For example,the searching result of the streamline query algorithm is still not accurate and the interactive method based on graph is not intuitive enough,which is difficult to understand,etc.This paper solves these problems with the new methods.First,in the streamline query,most of existing methods are related with features,which perform poorly on the whole shape similarity.So this paper proposes a query method based on finite sub-structure.It defines the finite sub-structure set and then uses the finite substructure to represent the streamlines.Then,the streamline querying could be transferred to the string matching problem,and we use the editing distance between the strings to evaluate the similarity between streamlines.Finally,to control the influence of the length of the line and reduce the cumulative error,this paper provides the control functions to make the query results more accurate.Secondly,in the interactive method based on graph,the graph model constructed by the existing methods is not intuitive and difficult to understand.This paper designs a new graph model,which can show the flow field structure more intuitively.Besides,we design two methods to explore the flow field,which are selection and drawing and local density control.By selecting and drawing,the user can more easily understand the relationship between the graph and the flow field.Through the local density control,the user can observe the flow field by controlling the streamline density in the region of interest.In order to realize the local density control,we propose a density calculation method based on grid,which can generate a multi-level density structure.When the number of streamlines is less,the user can observe the flow field structure.When the number of streamlines is larger,the user can observe more details.