Research On Interaction Technology Of Immersive Flow Visualization

Flow visualization is an important tool for converting flow data into graphic and images to assist users in studying fluid motion.Most flow visualization systems are limited to a twodimensional display interactive environment.It is difficult to provide users with effective depth information when analyzing three-dimensional flow field data,which greatly affects the user's data analysis experience and the efficiency of human-computer interaction.Immersive is a technology that displays graphics and images in three-dimensional space and allows users to interact with them through natural interaction.Immersive technology has been more applied to flow visualization due to its three-dimensional display and interaction.However,the current research in immersive flow visualization is still at primary stage.Most of Research is limited to immersive display or simple interaction with handles,which cannot meet the requirements of conventional flow visualization.This paper focuses on the technical and design issues of immersive flow visualization in immersive display and natural interaction.The following aspects of the immersive flow visualization interaction technology research are described:(1)A flow visualization method based on immersive augmented reality is proposed.This method displays the characteristics of flow field changes in the real space through streamlines.Since augmented reality devices do not have the computing ability required for flow visualization calculations.It uses the Server/Client architecture.The server is used for streamline computing and the head-set augmented reality device is used for streamline registration,result display and user interaction.It can superimpose and display the flow visualization results with in-depth information for users at the correct position in real space,and provide a reference for user analysis and decision-making.(2)On the basis of user interaction requirements,an immersive three-dimensional flow visualization natural interaction model(GG model)based on gaze,gestures,widgets,and boards is proposed.It defines gestures and interactive operations suitable for immersive flow Visualization.On this basis,navigation methods and interactive widgets based on user gestures are designed,as well as parameter configuration boards based on user gaze and gestures,to meet the user's navigation,space Interaction and parameter configuration requirements.Finally,based on the GG model,new interactive methods suitable for the streamline method of immersive augmented reality environment is designed based on the user's gaze: the seed point placement method based on gaze and gestures and the streamline layout method based on gaze.Subsequent experiments prove that the model can provide natural and efficient interaction for most flow visualization scenarios in immersive environment.(3)An immersive virtual reality flow visualization system that supports the full flow visualization process is implemented based on Leap Motion and HTC Vive Pro.The system provides user interaction flow management methods based on visual scenes and algorithm network management methods based on visual algorithm trees.GG human-computer interaction model is implemented based on VTK,Steam VR,and Leap Motion SDK;addresses continuous gesture jitter issues reflected in subsequent evaluations,A debounce method for gesture persistence protection is proposed to improve user interaction experience and enhance user interaction efficiency.The implementation of immersive virtual reality flow visualization system verifies the effectiveness of the GG model and provide a basis for subsequent model evaluation.(4)In order to verify the effectiveness of the above-mentioned interactive methods and provide valuable references for subsequent research,a variety of interactive method evaluation and comparison experiments based on the immersive virtual reality flow visualization system are carried out.For the GG model,an interactive task that simulates the conventional flow visualization process is designed according to the suggestions of experts.The GG model is compared with traditional two-dimensional interaction and handle interaction,and the interaction time,interaction difficulty,learning difficulty,fatigue and user preference are collected.For the seed point placement method based on user gaze and gesture,an interactive task for seed point placement is designed,and it is compared with traditional two-dimension interaction and interaction based on gesture controls,and the interaction time,interaction accuracy,Interaction difficulty and fatigue data.For the streamline arrangement method based on the user's gaze,the user's evaluation and suggestions are collected in the form of a scale.Experimental results show that the interaction method proposed in this paper can provide users with efficient and natural interaction,and can effectively improve the user's analysis experience.