Smoothing Meshes

The cloud of points you import in Digitized Shape Editor may be noisy, for various reasons,
mainly because of a poor digitalization accuracy on the edges of parts.
This noise is found again on the meshes computed from these clouds of points or imported
in STL format.

The consequences are:

• very noisy scans produced with the Planar Sections or Segmentations actions or
• the reconstruction of wavy curves or surfaces and/or of very high order. 

This can be partly avoided by smoothing the mesh.

• This action cannot be used on meshes with non-manifold edges.
• Since the volume of the part is reduced, some small facets may be inverted by the meshing.
  Therefore we recommend you alternate Mesh Smoothing and Flip Edges actions.
• Use the Activate function to process only a portion of a cloud.

1. Click Mesh Smoothing  and select a mesh.

2. The Mesh Smoothing dialog box is displayed.

3. Select the type of smoothing:

• Single effect if there is no sharp edge on the mesh to process.
  • Small radii will be erased.
  • The volume of the part will be reduced (contraction towards the center of gravity of the part).
• Dual effect to reduce the distance between outliers and the surface,
  and reduce the erasing of small radii. 
  • The reduction of the volume of the part is smaller.
  • A large displacement of one vertex inwards may cause the neighboring vertices to move outwards. 

4. Two other controls are available:

• Coefficient: It balances the effect of the new theoretical position in comparison
  with the original position.
  It varies from 0 (the vertex is not moved) to 1 (the vertex is moved to the computed position). 
• Max Deviation: Select this check box to control the maximum deviation allowed
  (the displacement will remain under the value set.)

  The deviation is the distance between a vertex and its initial position (not between its current position and that of the previous iteration). Therefore, if you want to control the maximum deviation, you have to check the Max Deviation option before the first Apply (it is no longer available after the first Apply). For a better appreciation of the quality of the intermediate meshes, the meshes are displayed in Flat Shading within the action.  In addition, for each step the maximum and the mean deviations (distances between a vertex and its initial position) are displayed in the dialog box.

5. Click Apply: a new mesh is computed.
   This action is an iterative one: click Apply again to smooth the proposed mesh. 

6. Click OK once you are satisfied.
   A Smoothing.x element is created in the specification tree,
   the original mesh is sent to the No Show. 

Examples:

Original part, before entering the action, i.e. in Smooth Shading:

Original part as you enter the action, i.e. in Flat Shading:

Dual effect, in Flat Shading

Dual effect, in Smooth Shading (after exiting the action)