SMS:Mesh Editing Workflow

To edit a mesh in SMS, use the following steps:

1. Check mesh quality.

1. Use contour display options. Turn off Points and Triangles, then turn on Contours in the Scatter tab of the Display Options dialog. Set contour options in the Contours tab. The "Color Fill" option is recommended for this. Look for inconsistent points (points with values much higher/lower than their neighbors or regions where no data points exist). Verify that the region being modeled is covered by the elevation/depth data and there are no holes. 2. Use an ARR Mesh Quality plot. Select Display | Plot Wizard to start the Plot Wizard. Select the "ARR Mesh Quality" option on the left and click Finish. Review plot window.

2. Post-processed mesh editing.

After the mesh have been created, there are several options for editing the mesh. 1. Delete extra elements. Select an extra element with the Select Elements tool. Use the Delete key to remove the extra element. 2. Delete thin triangles. Use the Elements | Select Thin Triangles menu command. Use the Delete key to remove the extra element. 3. Split quadrilaterals. Split quadrilaterals using one of two methods: To split individual quadrilaterals, use the Split/Merge Elements tool. To split all quadrilaterals in the mesh, use the Elements | Split Quadrilaterals menu command. 4. Merge triangles. Merge triangle using one of two methods: To merge individual triangles, use the Split/Merge Elements tool. To merge all triangles in the mesh, use the Elements | Merge Triangles menu command. 5. Merge multiple meshes. Select multiple meshes using the Shift key. Right-click on a mesh and select the Merge 2D Meshes command. Use the Mesh Merge Options dialog to specify how the meshes should be merged.

3. If needed, patch or pave elements.

1. Define area of mesh where the patch will be applied. Using the Create Nodestrings tool, create nodestrings enclosing the area to be patched. The nodestrings do need to create an enclosed area without any gaps. Four nodestrings are used to patch a paved area; three nodestrings are used to pave a patched area. 2. Convert section of mesh to the Map module. Using the Select Nodestrings tool, select the nodestrings. Select the Data | Mesh→Map command. In the Mesh→Map dialog, select the Nodestrings → Arcs option. Click on Create New Coverage. In the New Coverage dialog, select the Mesh Generator type. 3. Generate mesh with patch elements. Using the new Mesh Generator coverage in the Project Explorer, do the following: 1. Set vertex spacing on arcs to define mesh element size. Using the Select Feature Arc tool, select arc(s) and use the Redistribute right-click command. Use the Redistribute Vertices dialog to set the vertex distribution. 2. Create polygons in the Mesh Generator coverage. Polygons are not created automatically when arcs are enclosed. To create polygons: Use the Feature Objects | Build Polygons command. 3. Specify mesh type for each polygon (pave / patch / none). 1. Select a polygon and open the 2D Mesh Polygon Properties dialog. Use the Select Poylgon tool to select a polygon. Double-click on the selected polygon or use the Feature Objects | Attributes menu command. 2. Set the Mesh Type, Bathymetry Type, and Material Type for the polygon. Mesh types include Patch, Paving, Scalar Paving Density, and Constant Paving Density. Bathymetry type describes the elevation/topography source for the mesh nodes. Bathymetry types include a constant elevation value, interpolated elevation values from a scatter set, or interpolated elevation values from an existing mesh. Material types can be assigned to a polygon using materials previously created in Materials Data dialog. 3. Preview and edit the polygon mesh. Select the Preview Mesh button. Use the preview tools to edit the mesh. Set Arc Options to adjust distribution of vertices. Use Node Options to change how arcs are treated when using a patch mesh type. 4. Generate mesh from the Mesh Generator coverage. Select the Mesh Generator coverage and use the Map → 2D Mesh right-click command. Review the mesh quality for the newly generated mesh. 4. Merge meshes. Select multiple meshes using the Shift key. Right-click on a mesh and select the Merge 2D Meshes command. Use the Mesh Merge Options dialog to specify how the meshes should be merged.