Research On Calculating Viewpoint Quality And Selecting Viewpoint

The research of calculating viewpoint quality and selecting viewpoint is a hot issue in the field of computer graphics and virtual reality research area. For the purpose of quickly cognizing and understanding virtual scene, users should be provided with one or a series of best viewpoint, even an optimal path to roam the scenario. So users can access more scene information. This paper focusing on the calculating viewpoint quality and viewpoint selection has carried out several aspects of research as follows:·This paper first states the definition of viewpoint quality and analyzes why different viewpoint has different observation effects from the perspective of the three-dimensional observation mechanism and the spatial dimension. Then it further studies and compares three algorithms to calculate viewpoint quality. The three algorithms are viewpoint entropy algorithm, KL distance algorithm and feature information weighted algorithm under the observation channel model. Finally, it comes the conclusion that feature information weighted algorithm is more sensitive to viewpoint quality and its observation effect is better.·The selection of best viewpoint is based on reference viewpoint set which is achieved by sampling in the horizon ball. The sampling density decides the computational efficiency. In order to solve the conflicts between sampling density and computational efficiency, this paper uses particle swarm algorithm and the viewpoint in the virtual scene tends to the area where the viewpoint quality is larger. The particle swarm algorithm greatly improves computational efficiency.·This paper researches a special kind of observation style which is horizontal roaming around the center of the scene. According to viewpoint quality evaluation mechanisms, this paper evaluates observation effects in the candidate set and then determines the optimal pitch angle of the observation.·This paper studies how to design a route when the start point and the end point are given. This must satisfy two requirements: First, the viewpoint goes along the direction of high viewpoint quality; second, the sub-vector of the forward direction along the direction of the end point must be positive.·The selection of the viewpoint is not only related with the spatial information, but also related with the time information. Display the appropriate information at the right time. When simulation is replaying in the visualization system of data simulation, edit the viewpoints on the time domain and the spatial domain. When replaying again, play the playback file under the control of the viewpoint script file. This saves the users’ time to manually adjust viewpoint and frees them from tedious repetition labor.