Stage of geometry correction / simplification
Introduction
The third stage is the stage of correction of geometric defects and/or geometry simplification.
Correction principle
The principle of correction proposed by Flux for the various types of geometric defects is presented in the tables below:
Defect of the superposition type  Principle of correction  

Confused points  ⇒  Suppression of a point 
Superimposed lines

⇒ 
Cutting of the lines

Defect of the intersection type  Principle of correction  

Intersection of two lines

⇒ 
Cutting of the lines

Intersection of a line and a face  ⇒  Correction is to be made by the user 
Defect type  Principle of correction  

Line abnormal (value fixed by the user)

⇒ 
Removal of the L2 line by fusion of the lines L1 and L2

Face shorter than ... (value fixed by the user)

⇒ 
Removal of the F1 face by confusion of the lines L1 and L2

Open wire 
⇒ 
Closing of contour by prolongation of the L1 line 
Simplification principle
The principle of simplification proposed by Flux consists to remove some lines and points and thus “to reduce” the geometry. Simplification is expected only for the lines of the segment type and arc of circle type.
The principle of simplification is presented in the table below:
Geometry type  Principle of simplification  

Segments located on the tangent of the straight lines 
⇒ 
Removal of the lines L2 and L3 and suppression of the points P2 and P3 by fusion of the lines L1, L2 and L3

Arc of circle having the same curve angle 
⇒ 
Removal of the lines L2 and L3 and suppression of the points P2 and P3 by fusion of the lines L1, L2 and L3 
Algorithms of automatic correction / automatic simplification
To facilitate the process of correction, the algorithms of automatic correction / automatic simplification are proposed. They are presented in the table below:
The algorithm of …  enables the correction … 

automatic correction 
of all blocking defects (superimposed entities and intersections) 
automatic simplification  of all defects of type: abnormal lines 
Manual correction
To correct the other defects the user must carry out a manual correction with the tools presented in the table below. The use of these various commands is detailed in section Geometry correction / simplification of chapter Geometry / mesh importation: software aspects .
To correct the defect type ...  the user should ... 

Intersection of lines Superposition of lines 
Cut line on a point Cut line on intersection 
Abnormal line Abnormal face 
Decrease absolute precision by reducing relative precision (relative epsilon) 
Abnormal line (user epsilon) 
Fuse lines 
Abnormal face (user epsilon) 
Confuse lines 
Open wire 
Extend line to point Extend line to line 