Edge Bundling And Interaction Design In A Virtual Reality Environment

Classic geospatial network visualization tends to limit itself to 2D representation by organizing edges and nodes on a 2D map or the external surface of a traditional globe model.Due to the visual clutter caused by a large amount of edge crossings and nodeedge overlaps,efficient exploration of geospatial network visualization becomes challenging when the positions of the nodes in the network data are unchangeable as they carry useful geographical information.Therefore,the issue of how to effectively explore the visualization of geographical network has become even more urgent.First,this thesis proposes the Sphere Immersive Model(SIM),which contains a hollow sphere and sets the viewpoint at the center of the sphere.The world map texture could be mapped on the internal surface of the sphere.With the HMD on,users are given a continuous view of the interior globe space through arbitrary head movement.Moreover,this thesis proposes a dedicated VR interaction method for the intuitive exploration of geospatial networks.Second,to reduce visual clutter and reveal network patterns,this thesis proposes a parametrizable 5-step 3D edge bundling algorithm.Especially,to avoid the uncomfortable observation caused by the collision of network edges with the viewpoint,this thesis proposes a method that avoiding collision of viewpoint with control points.Third,this thesis has implemented the SIM and 3D edge bundling algorithm using Unity3 D in an immersive VR environment.We demonstrate the usefulness of our approach with two case studies on two real-world network datasets.They are the Global Flights Dataset and the UNHCR(The UN Refugee Agency)Refugee Dataset.Finally,this thesis conducts a user study to evaluate the usability and effectiveness of our 3D edge bundling algorithm in an Oculus Rift DK2 VR environment.The result shows that the 3D edge bundling approach helps to effectively improve the task completion time.