Research On 3D Reconstruction Based On Voxel Guidance

3D reconstruction technology is a major topic in the field of computer-aided design and an important means of geometric modeling.This paper first discusses and compares the existing three-dimensional reconstruction algorithms,and finally determines the three-dimensional reconstruction based on the constructed solid geometry-Constructive Solid Geometry(CSG).The significant advantage of the CSG method is that complex entities can be constructed by simple voxels,and the process of constructing entities can be recorded in detail,and voxel parameters can be easily modified.The predecessors of this topic have realized the extraction of geometric information in the three views of the project,completed the three-dimensional reconstruction of the basic voxels,and called the Open GL function to display the reconstructed basic voxels on the screen.However,this is not the final 3D model of the part.It is also necessary to obtain a 3D model of the part by means of a CSG tree and a voxel Boolean operation.In order to build a CSG tree,this paper proposes two ways of interactive construction and automatic construction.The automatic build efficiency will be high,and the interactive build reliability will be high,and the two can complement each other.Entity 3D Boolean operations have been completed by the research group earlier,which lays a solid foundation for the ultimate realization of 3D reconstruction.Voxel picking is the basis and premise for interactively building a CSG tree.This paper introduces the process of displaying three-dimensional objects in the world coordinate system on a two-dimensional screen.It combines the graphic display principle of Open GL to explain the coordinate transformation involved.This article uses Open GL's selection mechanism to pick up the elements on the screen.Create a name stack for the drawn primitives when publishing the drawing commands,and set a buffer to hold the selection information.The research method of the relationship between the research point and the polygon position realizes the grasping function of the mouse,and completes the picking of the upper element of the screen.The facet of the same voxel has the same name in the name stack,so that the voxel picking can be realized.Then,the Boolean operation type of two voxels is specified from the interface,and the CSG tree is constructed step by step.Through the software programming practice,the basic voxel picking operation and CSG tree construction are realized.In this paper,the algorithm of automatic construction of CSG tree is proposed.The algorithm starts from the inclusive relationship of the ring in the three views,and analyzes the positional relationship of the corresponding voxels.After obtaining the positional relationship of voxels,some automatic selection of Boolean operation types is proposed.A practical guideline.In this paper,VC++6.0 is used as the development platform,and the Open GL function library is used as the tool.The MFC framework is used to verify the functions described in the paper,and the reliability and feasibility of the functions and algorithms proposed in the paper are proved.