Research And Implementation On Online Triangulation For Portable Scanners

Reverse Engineering(RE)has been paid more attention and widely used with the increasing development of three-dimensional scanning technology and computer graphics.Surface reconstruction has been one of hot topics in the reverse engineering.Now,most triangulation algorithms achieve mesh reconstruction based on scattered point cloud data using post-processing ways.Based on point cloud data obtained by hand-held laser scanners,we in this paper implemented a new fast triangulation algorithm.First,we build an initial mesh between the adjacent scanning lines.Then we determine whether the scan lines intersect each other by comparing the initial mesh normal directions of the scanning lines.Based on the comparison results,we finally adjust the scan lines and produce a new triangular mesh.This paper mainly achieves the following works:(1)We preprocess the collected scanning line point cloud data.We remove the outliers by the fitting straight-line algorithm.Then we de-noise point clouds by Gaussian filter for scanning lines.We finally simplify the point clouds by the angle-and chord-union method.(2)We build an initial mesh between the adjacent scanning lines by the low-side-driven mesh method first,and then we determine whether the scan lines intersect by comparing the initial mesh normal directions of the scanning lines.Based on the comparison results,we finally adjust the scan lines and produce a new triangular mesh.(3)The mesh is generally with poor quality,which is constructed by the front triangulation algorithm.We optimize the triangular mesh through a topology optimization algorithm.