Research On Dynamic Ocean Data Visualization Based On Line Integral Convolution And Vector Line

Vector field visualization can effectively help people understand the laws contained in complex data sets.It is a research hotspot in scientific computing visualization.In this paper,we study the algorithm optimization of the method of line integral convolution and vector line.We made some improvements to the method of line integral convolution.In the two-dimensional steady flow field,when the background noise is white noise,we designed "cross" high-pass filtering to replace the traditional two-dimensional high-pass filtering,as a result,we can enhance the textures of streamlines more concentrated and strengthen continuity for each streamline.We use the method of interpolation to turn the discrete white noise into continuous white noise to solve the problem of discontinuity.When the sparse noise is used as input in the steady flow field,we change the direction of background sparse noise according to the direction of vector field to make the streamline clearer and brighter.We also provide random initial phase for every streamline to avoid the pulsation effect during animation.Method of ignoring integral calculation for the texture points of non-mainstream lines is used to solve the problem of rough streamlines.We change the streamline tracking constraints to solve the problem of obvious boundaries when stitching image.The velocities of vector field are encoded in the speed of the same length streamlines so that the moving speed of streamlines can express flow rate.In the two-dimensional unsteady flow field,we use double value scattering and "cross" high-pass filtering to enhance the contrast and continuity of the streamline texture.The main problem with the vector line method is the selection of seed points.We use the probability density method to control the density of streamlines in the vector field.Each particle head forms a probability density function influence domain,and the generation and disappearing of the streamlines are determined by the value of the function,thereby we can ensure a uniform and reasonable distribution of the streamlines in the vector field.For the streamlines that flow out of the boundary,we change its blanking method to make it gradually shorten,making it more in line with people's perception.For the region where the streamlines at the boundary flow to the inside of the vector field,the region will be vacant over time,we use the method of secondary drawing of the streamlines on the same trajectory to solve this problem.Finally,by using our improved methods combined with ocean currents and storm surge data,we can generate high-quality images and animations,and we can see that the visualization has been significantly improved in many ways.