# Stage of geometry checking

## Introduction

The second stage is geometry checking. This stage is the stage of research (identification) of the geometric defects; correction will be carried out in the following stage (stage 3).

Before describing the modes of defects search, the different defect types are described in the following blocks.

## Geometric defects

The geometric defects can hinder or block the geometry building process.

The following can be therefore discerned:

• blocking defects (intersections and superimposed entities):

these defects must be identified and corrected before building the geometry in Flux

• non-blocking defects (very small lines and faces, wires not closed, …):

these defects do not impede the geometry building in Flux, but they can influence in a negative manner the quality of the geometry building and/or the meshing

The geometric defects are presented in the table below:

Defect Example (or type) Consequence
blocking
• intersection type:
• line-line
• line-face
• face-face*
• superposition type:
• confused points
• superimposed lines
• entities of small dimensions:
• abnormal line
• abnormal face
building of the faces and volumes impossible
non-blocking
• entities of small dimensions:
• abnormal line (user epsilon)
• abnormal face (user epsilon)
difficulties of meshing
• open wire
missing face

* In the next figure, the faces building after the import of the geometry will generate the intersection of the faces. This type of defect is not identified by Flux in the Geometric defect entity, but it is blocking for the further volumes building. Connecting the points P1 and P2 by a new line before the faces building enables to avoid the intersection of the faces.

## Defects research modes

The research of the geometric defects can be carried out in two ways:

• for the assembly of types of defects (described as global checking of the geometry)
• by type of defect (described as research by type)

## Research result

Whatever the default research mode, the result is the following:

• Flux creates a geometric entity of the Geometric defect type for each defect found (this entity contains the information about the defect localization: number of concerned points, lines or faces)
• Flux highlights this entity in a graphic window (specific display)