关键词: 非均匀B样条曲线, 步长自适应, 追踪法, 曲面求交

Abstract:

For the integral modeling of objects with composite surfaces, it is necessary to stitch up the single-sided patches with gaps. Traditional surface intersection technology has many shortcomings, which can not meet the requirements of intersection accuracy and intersection speed at the same time. Regarding this an optimal tracing method is proposed for surface intersection. Five degree non-uniform B-spline is used as a fitting curve. The tracing step size is correlated with the curvature at the end of the intersection line in the process of intersection, which can make the step size change in real time according to the specific environment. The intersection algorithm is stable, accurate and fast. The intersection process of different surfaces is realized in Surface Reverse, a self-developed reverse system. The experimental verification is carried out based on the fixed step tracking method and the improved step-adaptive tracking method. The results show that the improved tracking method not only has less computation and shorter time, but also has less intersection lines when the intersection line error is less than 0.001 mm. The accuracy can reach above micron level. This intersection algorithm is stable, accurate and fast.

Key words: non-uniform B-spline curve, adaptive step, tracking method, surface intersection