How to Relax or Refine a Mesh in SMS

Are you ever tempted to refine your mesh after creation using the mesh editing tools? Manually changing hundreds or thousands of mesh elements using the mesh tools can be very time consuming.

Although possible to use the mesh tools, it is better to recreate a new mesh when wanting to refine or relax the elements. This will maintain the accuracy of your mesh, and reduces possible issues that may arise later on in the project due to inconsistencies that editing manually creates.

To recreate a refined or relaxed mesh:

1. Create a mesh generator coverage.
1. If the existing mesh was created from a mesh generator coverage, you can use that coverage or a duplicate of that coverage.
2. If a mesh generator coverage does not exist, you can create a mesh generator coverage by converting the mesh boundary or nodestrings to a new mesh generator coverage.
2. Go to your mesh generator coverage and redistribute the vertices so that there are either more or less arc segments depending on what you are trying to accomplish with your model. To relax the mesh, fewer arc segments are desired, and to refine the mesh more arc segments are desired.
3. Assign the desired meshing type (paving, patch, etc.) to the polygons in the mesh generator coverage and set the bathymetry source to use. Be certain to preview how the mesh will generate with the new spacing for each polygon.
4. Now generate a new 2D mesh using the edited mesh generator coverage.
5. Add the new mesh to your model simulation and run the model using the relaxed or refined mesh.

Sometimes you might not want to relax ro refine the entire mesh. To only relax ro refine part of the mesh do the following.

1. Create a new mesh generator coverage.
2. Create a polygon in the area of the mesh you wish to relax or refine.
3. Redistribute the vertices along the arcs in the polygon to so there is a great or fewer number of segments along each arc.
4. Set the meshing type for the polygon and assign it a bathymetry source. Be certain to preview the mesh for the polygon to be certain you are getting the mesh you want.
5. Generate a new 2D mesh for the area being refined or relaxed.
6. Select both 2D meshes and merge them together.
7. Add the new merged mesh to your model simulation and run the model.

Using these steps when editing a mesh can make a huge difference in your model and save you time. Try out relaxing and refining meshes in SMS today!