Research On Three-dimensional Image Wrapping Algorithm Based On Bounding Box

With the augmentation of the virtual reality technology,the established three-dimensional model in virtual space becomes more and more delicate and vivid,lead to increase in the number of data model and complicated,followed by two models when collision occurs,the detection algorithm between them is complicated,so the strong immersive virtual scene of the relationship between the collision detection algorithm with good performance are inseparable.Collision detection is always a hot issue to be solved in virtual reality technology.Its purpose is to judge whether there is intersection between various models in virtual space,so as to make a reasonable response in time.In this paper,the application of virtual reality technology in the field of stomatology education is taken as the research background.Based on the existing collision detection system framework,two stages of collision detection,namely rough intersection detection and precise intersection detection,are studied.Combined with the background of the subject,an improved scheme for three-dimensional image wrapping algorithm is proposed,and the improved algorithm is verified by experiments.The main research content of this paper is bounding box technology and its intersection detection,mixed level bounding box tree and pixel intersection test.1)Bounding box technology and intersection detection between them.In this part,the principle of bounding sphere,axial bounding box,directional bounding box,discrete polyhedral bounding box and ellipsoid bounding box and the intersection detection algorithm among bounding boxes are described in detail.In this paper,an intersection detection algorithm based on Hill sorting is proposed,and compared with the traditional I-Collide algorithm,the proposed algorithm achieves an average detection speed of about 16.53%.2)Hybrid hierarchical bounding box tree.According to the research of collision between rigid bodies,a suitable bounding box is selected to construct a hierarchical bounding box tree.In this paper,two factors affecting the structure of hierarchical bounding box tree are analyzed,that is,the degree and construction mode of hierarchical bounding box tree and the traversal mode of hierarchical bounding box tree.For a single hierarchical bounding box,both compactness and real-time performance cannot be well considered.Therefore,this paper proposes to adopt the mixed structure of bounding ball and axial bounding box as the root node,and use binary tree and top-down construction to traverse the tree with large node bounding box first.3)Pixel intersection test.In the stage of accurate intersection detection,the triangle wrapped by the leaf nodes still intersecting in the BVH tree is further judged.In this paper,Devillers?Guigue algorithm is used to transform the vertices of two triangles into a fourth-order determinant,and the geometric meaning of the determinant is used to determine whether they intersect.After completing rough detection and precise detection,four virtual scenes containing different cloud numbers and different object intersection states are simulated,which has good collision detection effect.The comparison of data between frame rates of different scenes proves the real-time performance of the system in this paper.