# Smoothing

Smoothing is used to adjust the locations of element corners (nodes) to reduce distortions in these elements.

To apply smoothing to the elements of your mesh:

1. Display a mesh or a submesh in the 3D viewer.

2. In the Modification menu select the Smoothing item or click button in the toolbar. The dialog box contains the following fields which should be specified:

- Id Elements field allows to specify the elements which should be smoothed by selecting them in the 3D viewer (lock Shift button to select several elements).

- Select whole mesh, submesh or group - smoothing is applied to the whole mesh or its part.

- Fixed nodes ids: some nodes keep their location during smoothing. If a mesh is built on a geometry shape, the nodes built on geometrical edges are always fixed. If smoothing is applied to a part of a mesh then the boundary nodes of an elements set are also fixed. Any other nodes may be additionally fixed.

- Smoothing Method:

- Laplacian smoothing pulls a node toward the center of surrounding nodes directly connected to that node along an element edge. Centroidal smoothing pulls a node toward the element-area-weighted centroid of the surrounding elements. Typically, the Laplacian method will produce the mesh with the least element distortion. It is also the faster method.

- Centroidal smoothing usually produces a mesh that has more uniform element sizes. Both methods produce good results with "free" meshes.

- Iteration limit: both of the smoothing methods use an iterative procedure to converge toward a smoothed mesh. All nodes are smoothed according to one of the techniques shown above. Then the smoothing is reevaluated with the updated nodal locations. This process continues until the maximum number of iterations has been exceeded, or all elements has aspect ratio less or equal than the specified one.

- Max. aspect ratio.

3. Click the Apply or OK button to confirm the operation.

See Also a sample TUI Script of a Smoothing operation.