Rapid algorithm of quasi-rectangular object bounding box

Abstract

The invention relates to a rapid algorithm for a quasi-rectangular object bounding box, and the algorithm comprises the following steps: 1), reading an object, and obtaining the ID of the object; 2) traversing all feature IDs of the object; 3) constructing a Z-axis vector and a Y-axis vector; 4) performing cross multiplication on the Z-axis vector and the Y-axis vector to obtain an X-axis vector;5) constructing a temporary coordinate system: 6) calling an AABB bounding box in the temporary coordinate system to obtain the minimum bounding box of the object, and outputting the sizes of the bounding box in the X, Y and Z directions and the coordinates of the left lower corner and the right upper corner of the box; and 7) setting the temporary coordinate system as WCS, and drawing and displaying the bounding box according to the parameters of the bounding box. According to the method, the defects that an existing AABB algorithm, an OBB algorithm and other algorithms are low in efficiency,complex in processing process and the like are overcome, the calculation time of a computer is shortened, the calculation time of the bounding box is controlled within 0.1 s, and engineering application of the algorithms is facilitated.

Description

【Technical field】 [0001] The invention relates to a design method of a packaging box, in particular to a fast algorithm for a bounding box of a similar rectangular object, and belongs to the technical field of computer graphics processing. 【Background technique】 [0002] The minimum bounding box of spatial objects is widely used in the fields of packaging engineering, image processing, pattern recognition, collision detection, mold parting design and mechanical control. A bounding box is a simple three-dimensional geometric space. At present, the main types are sphere, axis-aligned bounding box (AABB), oriented bounding box (OBB), 8-DOP, and convex hull. In practical applications, people hope to have both the smallest bounding box size and fast results, and the two are often exclusive. In engineering applications, people often put the first priority on the ability to quickly calculate the results, taking into account the dimensional accuracy. [0003] The existing bounding...

AI Technical Summary

Problems solved by technology

[0016]1. In the OBB algorithm proposed by Chen Hua, the coordinate system of the object to be solved is rotated around three orthogonal axes by n3 Second, its time complexity is O(n3), the efficiency is very low, and the accuracy of the bounding box depends on the rotation step. The smaller the step, the higher the calculation accuracy, but the calculation time will increase significantly , the calculation time usually ranges from tens of seconds to hundreds of seconds

[0017]2. Hu Zhigang and Qin Qifei proposed a closed directed bounding box generation algorithm based on the minimum volume of the convex hull for the given 3D point cloud data of the object. The complexity is reduced to O(n3 / 2(logn)2); Sun Dianzhu et al. have avoided enumerating and solving various postures of objects through genetic algorithms, and can Quickly solve the approximate minimum bounding box of the object, and the time complexity is O(mnG); the above two algorithms are mainly aimed at point cloud models, and cannot handle solid models. They are mainly used for reverse engineering, and their application range is narrow

[0018]3. Chen Songbai and others quickly obtained the main direction of the object through principal component analysis (PCA), and the processing object is the triangular patch on the solid surface. The complexity of the box algorithm is reduced to O(n), but the object needs to be discretized before calculation, and the operation is complicated

[0019]These algorithms can accurately calculate the bounding box of any complex three-dimensional object, but they have the disadvantages of long calculation time and the need to discretize the model, which affects the Engineering Applications of Algorithms

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