To conquer the low efficiency of topological establishment problem

according to the characteristics of graph model with directed rings

propose a robust polygon construction algorithm here.Firstly

this algorithm makes the lines data into graph and preprocesses the graph model;Then

form rings according to graph model

and judge if the valid ring is hole or shell based on the direction of forming the directed rings.At last

assign the holes to the corresponding shells.The number of shells is the number of polygons.This algorithm can solve large-scale lines data forming polygons effective problem

at the same time

compare with mixed model

element model and simple element model.in this algorithm we adopt quadrant tree index and R tree index which have high effective.Quadrant index in experiment is 5.400 s faster than element model

and 3.641 s faster than simple element model when dispose the same data(namely

with the 93664 quantity of line data to form polygon data).Experiment result shows this algorithm effecting is better than others.