Objective

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The development of 3D reconstruction technology has led to the wide application of 3D scanning technology in the cultural relic reconstruction and reverse engineering industries. However

scanning models usually include many holes after reconstruction due to the scanning environment

scanning techniques

and other factors. Models with holes affect follow-up application in the cultural relic reconstruction industry and industrial reverse industry. Radial basis function has been widely used in repairing holes. However

implicit surfaces based on radial basis function are sensitive to noise data. Therefore

they cannot be efficiently used in noise hole filling. This study proposes an improved hole-filling algorithm based on radial basis function. The algorithm mainly consists of smoothing noise data

interpolation subdivision hole structure

and radial basis function. In this way

the proposed algorithm can resolve the boundary mutation problem for noise hole repair.

Method

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First

the algorithm uses the Laplace function to smooth the boundary of noisy holes. We use the topological structure of adjacent triangles on the model to check the boundary of holes and identify holes. After identifying holes

we smooth their boundary by multiple neighborhoods before building an implicit surface. The algorithm uses the smoothed data to solve the implicit surface on the basis of the radial basis function. Second

the algorithm subdivides the holes by applying the fast center of gravity interpolation method for regular holes. The gravities of boundary and convergence are used to perform a subdivision process. Third

the algorithm combines the curvature features around the holes to make the filling holes consistent features with scanning data. Therefore

boundary and normal constraint points are used to define the implicit surface solution. The boundary constraint points are taken from the multiple neighborhoods from the boundary of holes

and the normal constraint points are taken with the constraint of normal direction. Finally

the algorithm adjusts the interpolation point with the gradient descent method. The points of interpolation subdivision holes are usually not on the scanning surface of the holes. The algorithm uses the obtained implicit surface equation to find the partial derivative to adjust the interpolation points to the scanning surface rapidly. We use the gradient descent method and the setting error threshold to adjust the interpolation points of holes. In this way

we can achieve smooth patch of filling results.

Result

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3D classical models and actual mechanical workpieces are scanned to verify our algorithm. The comparison experiment is conducted by applying the wave-front method and Geomagic software method to the same holes. Our algorithm uses a preprocessing method for smoothing holes and keeps the curvature features around the holes. An implicit surface based on the radial basis function is applied to ensure the smoothness of repairing holes. The repairing holes become highly consistent with the surrounding curvature. The experimental results show that the proposed algorithm based on radial basis function is adaptable to noise holes. The results of this algorithm are consistent with the curvature variation around the holes. Therefore

the filling results are natural and smooth. The algorithm is a good way to improve the existing problems of edge mutation and trace obvious.

Conclusion

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The algorithm solves the noise sensitivity problem of implicit surfaces based on radial basis function by the curvature features around holes. However

the results of the algorithm are not ideal for filling some complicated holes. The fast barycentric interpolation function also has limitations for irregular holes.