Research On The LOD Parameters Setting Based On RTT System

As the demands of people applications increased, the3D scenes rendered by computerwere becoming more and more complex. So how to balance and coordinate the contradictionbetween the3D scene’ realistic and real-time rendering has become an important issuerestrained the development of virtual reality technology. However, the remarkable resultshave been achieved by the LOD (Level of Detail) technique in solving this problem. Most ofthe previous researches on the LOD technique have mainly focused on the automaticgeneration and rendering technologies. But research on the LOD parameter settings for thespecific surfaces from the user’s viewpoint was rare. In addition, the RTT (RealtimeTechnology) is applied in virtual display area more and more widely in recent years. So theparameter settings of the LOD based on the RTT system become more and more important.This paper has investigated the researches of the LOD technique and the applications ofthe RTT system from home and abroad, then found that most of the researches on the LODtechnique focused on the automatic generation and rendering. Besides, the RTT system wasapplied more and more widely. So this paper has studied how to setup the LOD for thespecific surfaces correctly and quickly based on the RTT, and then how to use the RTTsystem to display and evaluate the automotive models based on the LOD parameter settings.About how to setup the LOD for the specific surfaces quickly and correctly in the RTTsystem, this paper has analyzed the factors affected the LOD selection in the RTT systemthrough a lot of experiments, and found that the distance between viewpoint and the model,radius of curvature, light intensity, relative speed of motion can affect the LOD selection tosome extent. Then the factors studied in this paper have been selected according to the actualsituation, and then the experimental formula between the deviation and influence factors hasbeen obtained by using the method of regression polynomials. The experimental formula can help users to generate the accurate LOD for different models more quickly. As an example, a3D model of BMW M6has been established to verify the experimental formula. The resultsshow that the experimental formula is effective.In addition, the appropriate LODs for the exterior panels of BMW M6using theexperimental formula have been created, and then the model has been displayed andevaluated with the virtual reality technology based on the RTT system. This method ofvirtual display and evaluation allows designers to interact with the products moreperceptively. It can save the time of shape description, thus shorten the period of productdevelopment, then reduce the development costs. It provided a new method of descriptionfor large-scale data visualization. It was helpful to the rapid design and development ofvehicle.