SMS:2D Mesh Polygon Properties

File:2D Mesh Poly Properties.jpg

2D Mesh Polygon Properties dialog

The 2D Mesh Polygon Properties dialog is used to set meshing options for the conceptual model. See Mesh Generation for a discussion of the conceptual modeling approach.

To access the 2D Mesh Polygon Properties go to Feature Objects | Attributes. The 2D Mesh Polygon Properties dialog will open. Double-clicking inside a polygon will also bring up the 2D Mesh Polygon Properties.

The following polygon attributes can be set:

• Mesh Type – Specify the mesh generation algorithm. The following options are available:

• Patch
• Paving
• Scalar Paving Density.

• Bathymetry Type – Specify the bathymetry source for assignment to the mesh. The following options are available:

• Constant – Assigns a constant elevation value to all nodes in the mesh
• Scatter Set – Interpolates elevation values from the specified scatter set
• Existing Mesh – Interpolates elevation values from an existing 2D mesh

• Material – Material type to assign to elements created within the polygon
• Arc Options – Used to modify the feature vertices along the arc. The arc must be selected in the polygon preview window. The following options are available:

• Use Original Vertices
• Distribute Vertices – Change the number of vertices along the arc. A bias can be specified rather than distributing the vertices with a constant spacing.

• Node Options – When the mesh type is set to Patch, the node options are used to define the 3 or 4 sides for the patch mesh generation. If a feature point is selected in the polygon preview window, the following options are available:

• Split – The mesh generation algorithm will treat the two arcs meeting at the feature point as separate sides.
• Merge – The mesh generation algorithm will treat the two arcs meeting at the feature point as a single side.
• Degenerate Edge – The mesh generation algorithm will treat the two arcs meeting at the feature point as a "degenerate edge." When using a degenerate edge, the Patching algorithm will require only 3 sides to be defined. This option is only valid for meshes which allow triangular elements. Only one degenerate edge can be specified per feature polygon.

Mesh Preview

The preview area lets the user see and edit how the mesh will appear after the polygon has been converted to the Mesh module. This area has the following tools and options:

• Preview Mesh – The preview area does not update automatically. Clicking this button will display how the mesh will appear after conversion. After any options in the dialog are changed, this button must be clicked again to show the changes.

Preview Tools

The following tools are available for the 2D Mesh Polygon Properties dialog. Changes that are made to the polygon, such as adding a vertices or moving a node, will be made to the polygon once the dialog is closed by clicking OK. When nodes or vertices are moved, a preview can also be seen in the main graphics window if the dialog is not covering the changed area.

• File:Select Feature Point or Node.bmp Select Feature Node – Allows selecting a node which can then be moved to change the shape of the polygon.
• File:Select Feature Vertex icon.bmp Select Feature Vertex – Allows selecting a vertex which can be deleted or moved to change the shape of the polygon.
• File:Create Feature Vertex icon.bmp Create Feature Vertex – Adds a vertex along an arc belonging to the polygon.
• File:Tool Pan.GIF Pan – Moves the what portion of the polygon is visible in the preview area.
• File:Tool Zoom.GIF Zoom – Magnifies or shrinks the polygon in the preivew area.
• File:Frame.JPG Frame – Centers and resizes the polygon to fit in the preview area.
• File:Delete icon.bmp Delete Selected Feature Vertices – Removes the selected vertex from the polygon.

Related Topics

• Feature Objects
• Map Module Menus