SMS:Mesh Creation Workflow

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

1. Define model limits (domain).

1. Create a Mesh Generator coverage in the Map module. Create a new coverage with the "Mesh Generator" type. 1. Create new coverage from scratch. Select Map Data in the Project Explorer and use the New Coverage right-click command. Use the New Coverage dialog to create a new coverage by selecting the desired coverage type, and naming the coverage. 2. Create new coverage from an existing coverage. Use the Duplicate command on an existing coverage. This will copy any feature objects on the coverage. Use the Rename command to give the coverage a new name. Change the coverage type. 2. Digitize arcs to define domain edges. 1. Create feature arcs, nodes and vertices. With the Mesh Generator coverage as the active coverage, create feature objects. Use the Create Feature Arc tool to create arcs in the map coverage. Begin creating a new arc by clicking in the graphics window at either arc end. If clicking on an existing feature node, vertex or arc, the new arc will snap to that object. Double-click or press the Enter key to terminate the arc. Use the Create Feature Node tool to create additional nodes alone or to split arcs. 2. Modify arcs. Feature arcs often need to be edited after initial creation. 1. Create additional vertices on arcs. Use the Create Feature Vertex tool to add vertices along arcs. 2. Refine the arc shape. Use the Select Feature Vertex tool and the Select Feature Node tool to move/edit existing arcs and refine the shape by dragging the nodes/vertices. Use the Select Feature Arc tool to move entire arcs . 3. Split arcs. An existing arc can be split by: 1. Converting a vertex to a node. Use the Select Feature Vertex tool and right-click on a vertex along an arc. Select the Convert to Node command to split the arc into two arcs. 2. Add a node the arc. Use the Create Feature Node tool to add a node on an arc in order to split it into two arcs. 3. Add a new connecting arc. Use the Create Feature Arc tool to start or end a new arc on an existing arc to split the existing arc into two arcs. 4. Use the Split Arcs Tool. Right-click on an arc using the Select Feature Arc tool and select the Split Arc(s)... command. Use the Split Arcs Tool to divide arcs. 5. Split overlapping arcs using the Clean Options dialog. Select overlapping arcs using the Select Feature Arc tool. Use the Feature Objects | Clean command to bring up the Clean Options dialog. Select the Intersect selected arcs option (for selected arcs) or Intersect arcs option (for all overlapping arcs) to split the arcs. 4. Merge arcs. Two arcs that share an end node can be merged together. Select the shared node using the Select Feature Node tool. Right-click on the node and select the Convert to Vertex command to merge the arcs. If desired, the Select Feature Vertex tool can be used to select and delete the new vertex. 5. Smooth arcs. The variability or roughness of an arc can be reduced. Right-click on an arc using the Select Feature Arc tool and select the Smooth Arc(s)... command. Use the Smooth Arcs Tool to reduce the variability of the arc. 6. Prune arcs. Concave sections of the arc can be removed. Right-click on an arc using the Select Feature Arc tool and select the Prune Arc(s)... command. Use the Prune Arcs dialog to remove concave sections. 7. Extend/trim arcs. Extend or shorten an arc to match an existing arc's length. Using the Select Feature Arc tool, select two intersecting arcs. Right-click on an arc using the Select Feature Arc tool and select the Extend/Trim Arc... command. Use the Trim/Extend Arc dialog to select the target arc and source arc. 3. Generate domain extent arcs from other data sources. Domain extents can be created from data outside of the Map module by converting the data to a mesh generator coverage. 1. Convert GIS objects to a map coverage. 1. Convert raster data to feature objects. Converting raster data to feature objects can be done in one of two ways: Right-click on the raster data and select Convert To | Feature Objects which will create a new map coverage with arcs along all contours. Right-click on the raster data and select Convert To | Feature Objects at Elevation and enter a contour elevation to create arcs in a new coverage along the specified elevation. 2. Convert shapefile data to feature objects. Select a shapefile dataset in the GIS module and use the Mapping | Shape→Feature Objects command. Use the GIS to Feature Objects Wizard to specify how the shapefile attribute will be converted. 2. Convert a scatter dataset to a map coverage. 1. Convert a scatter contour value to a map coverage. Select the Data | Scatter Contour→Feature command. Use the Create Contour Arcs dialog to create arcs along the contour elevation into an existing coverage. 2. Convert scatter boundaries to a map coverage. Select the Data | Boundary→Feature command. Use the Select Coverage dialog to create a new coverage for the arcs or have the boundary arcs created on an existing coverage. 4. Merge domain coverages. If domain extents have been created on multiple map coverages, these coverages need to be merged into a Mesh Generator coverage. Select multiple coverages that have feature objects which need to be on the same coverage. Use the Merge Coverages right-click command. Right-click on the new coverage and set the correct coverage type. Use the Clean Options dialog to resolve conflicting feature object data in the new coverage.

2. Generate Mesh.

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.