This dialog is used to set the attributes for feature polygons with a SEEP2D or FEMWATER coverage. Attributes that can be specified for each polygon include:
Mesh Type
Set the meshing type to be used to fill the interior of the polygon. The options include (different options are given according the coverage type):
None. This results in a hole in the finite element network (no elements are created inside the polygon).
Adaptive Tessellation. Fills the polygon using Adaptive Tessellation. The bias tells GMS to favor the creation of large or small elements. Decreasing the bias will result in smaller elements; increasing the bias will result in larger elements.
Patch. Fills the polygon using patches.
Paving. Fills the polygon using a paving technique.
Polygon Type/Material
Polygons can be assigned a material type.
Graphical Tools
The Polygon Attributes dialog includes a preview window on the left side. This window shows the arcs and nodes of the selected polygon and allows the user to interact with that definition. The Preview button generates the elements that will be created for the polygon. It is recommended that the preview is used with the patch and adaptive tessellation options only due to the time required performing density meshing. There are several tools for modifying the existing polygon. Zooming, panning and framing work in the preview window just as they normally would in the graphics window of GMS. They are used to facilitate the selection tools.
All entities are selected by clicking on the entity or by dragging a box to select several entities after selecting the tool:
Select Vertex. Select
a vertex in the window (red point on arc). Drag the vertex to move it.
Create Vertex. Create
a vertex by clicking on a red arc.
Select
Node. Select a large blue or red node in the window.
Select
Arc. Selects arcs in the preview window.
Arc Options
The options dealing with selected arc(s).
Use original n nodes. Use the original vertices on the arc (before entering the dialog). If a vertex is moved, deleted, or created using the above tools, clicking this option will not undo the vertex.
Distribute n nodes. Specify the number of nodes and vertices to put on the arc (minimum of 2). The nodes are evenly spaced if the Bias is 1.0. A Bias of 2.0 will space the nodes more densely to one side; the last space will be twice as big as the first space. A Bias of 0.5 swaps this; the first space is twice as big as the last.
Node Options
The options dealing with selected node(s). These options are used for patches. Patches require 3 or 4 edges. An edge is an arc segment from one blue point to another blue point.
Split. Split two merged arcs. This turns the node blue.
Merge. Merge two arcs. This turns the node red.
Degenerate Edge. This works with 4-sided patches. The degenerate node is treated as an edge, as shown in the figure below.
Delete Vertex
Delete a selected vertex
Related Links:
Creating 2D Meshes
Coverages
Map -> 2D Mesh