Research On Quick Gridding And Model Rendering Of Scattered Point Cloud Based On GPU

With the development of computer graphics,3d reconstruction technology based on point cloud has been more and more widely used in the fields of virtual reality,machine vision and reverse engineering,and the related software and hardware technologies have also been developed rapidly.The accuracy of point cloud acquisition equipment is constantly improved,point cloud is more convenient,and the reconstruction process is more flexible.The resulting problem is that the collected point cloud data shows a massive increase,and many projects have a high requirement on the real-time performance of model reconstruction,which puts forward higher requirements on the existing point cloud reconstruction algorithms,especially the algorithm efficiency in grid model construction and rendering stage.Centering on the problems of rapid meshing of scattered point cloud and model rendering,this paper deeply studied key technologies such as point cloud data structure and rapid construction of grid model,real-time rendering of grid model,and designed and implemented a scattered point cloud rendering system.By improving the octree node data structure and designing two lookup tables,the construction of octree data structure based on GPU was realized.On this basis,the GPU Poisson reconstruction algorithm was proposed.The poisson equation was solved by GPU parallel algorithm,and the point cloud grid model was constructed by using GPU Marching cube method to extract isosurface,which improved the efficiency of grid construction by 10 times.In the rendering stage of grid model,LOD progressive grid is generated by preprocessing in parallel to save grid folding information and reorder grid data.During rendering,LOD model was selected with the projected area of the mesh bounding box on the screen as the weight.GPU streaming frame consistency algorithm was adopted to generate the LOD grid that needs to be rendered for the current frame.Finally,VOBs technology was used for rendering to realize real-time rendering and interaction of the grid model.In order to verify the implementation effect and efficiency of the algorithm in this paper,OSG is used as the rendering engine and embedded in the QT written UI interface to design and implement the scattered point cloud rendering system.Point cloud model loading and LOD model information and folding information output are realized through interface interface.Algorithm parameters are set through parameter setting interface,and the results are displayed at the end of algorithm execution.Through experimental tests,the point cloud meshing and model rendering methods presented in this paper have achieved the expected results.