Detection and Simplification of small lines


Some lines may be considered small and problematic for the mesh (unnecessary overload). It is possible to detect small lines according with criteria and then to simplify it according to the neighborhood.

Criteria of detection

Small lines are detected according to several criteria:

  • An absolute or relative criteria:
  • absolute value: all lines with a length smaller than the user length are detected
  • relative value: computed ratio must be less than the user ratio
  • A line can be detectable if it be isolated (i.e. it should not be more than one other line connected to each of its extremities)

Detected small lines appear graphically and are stored in the data tree as geometric defects entities.

Relative criteria

Computed ratio < User ratio


  • Computed ratio =
  • User ratio = value required to the user in the box New Detect entities

Detection: example 1

Here is an example to illustrate the choice of criteria (user ratio).

Example 1
User ratio chosen = 0.015

Detection: example 2

Here is an example where the small line is not detectable.


Once small lines detected, the user can simplify it using the command of simplification.

The command of simplification of small lines is applied only on geometric defects entities of type “small line”.

The simplification is to merge the small line detected with neighboring lines if possible.

After successful simplification, the geometric defect disappears from the date tree and disappears graphically.

Simplification condition

For a detected small line is mergeable with neighboring line, lines must be:

  • collinear and / or tangent
  • free (not linked to other entities preventing the merge)


The different accesses of the operations of Detection and Simplification small lines are:

  • Detection:
    • By menu: Correction&Simplification > Detect entities > Detect small lines > New
    • By icon:
  • Simplification:
    • By menu: Correction&Simplification > Simplify entities > Simplify small lines > New
    • By icon: