# Boundary Surface Panel

Use the Boundary Surface panel to show the various boundary types, for example, wall, inlet, outlet and baffle, defined when the data was input.

Structured boundary files enable boundaries on structured data. Different types of boundaries may be grouped together and displayed as one surface, with all of the standard display options available for other surfaces. Boundary surfaces have an additional display option that is not available for other surfaces, called outline edges.

Keyboard shortcuts simplify the selection of entries within a list. Use Ctrl (M1) to select individual entries, or select a range of entries with M1 to mark the start of the range and Shift [M1] to mark the end.

If the data reader did not define any boundary types on input, clicking Create on the Boundary Surface panel produces the following error message: There are no boundary types defined for any datasets.

Outline edges will display only as geometry colored with no mesh or contour overlays and is ignored for integration. It is intended as a visual aid only.

Why use the Boundary Surface panel?
The Boundary Surface panel can display any or all of the boundary types that have been identified in your input file. This can be used to verify proper boundary conditions by showing the scalar and vector values on the various boundaries. It is also a convenient way to display the geometric shapes that bound the flow.
How do I create a surface showing the boundaries?
In order to show the boundaries for your model, the input data must identify the boundary types. Currently, unstructured data readers support this option directly. Boundaries of structured datasets are supported with structured boundary files. If the data has the correct information click Create on the Boundary Surface panel to create a surface. Note that this will allow you to create boundary surfaces on the current dataset only. If you wish to create boundary surfaces on a different dataset, you will have to change to another dataset. You can do this with the Dataset Controls panel or by "quick-picking" on an object in another dataset. When you click Create, all of the possible boundary types will appear on this panel. Next, select one or more of the boundary types to be displayed from the boundary type selection area. To select a boundary type, press M1 when the cursor is positioned over the name of the desired type. When a boundary type has been selected, the name is highlighted. Clicking on a selected boundary type will deselect (and un-highlight) that choice. Once the boundaries have been selected, click OK. Certain actions, such as changing the display type, will cause the newly created surface to be visualized and function as implicit OK clicks.
What are the display options for boundary surfaces?
The boundary surface may be colored by a geometry color or a scalar color. It may be shown as vectors by selecting that option in the surface type area or the surface may be shown as a constant, faceted or smooth shaded surface, a mesh or a series of contour lines. These options are available in the display type option menu. The computational mesh may also be shown on top of the surface by clicking show mesh.
Boundary surfaces contain a unique display type, called outline edges. This option displays the outline of the surface. Note that the outline edge option will draw only those edges on the border of the surface (edges shared by only one polygon) or where the surface normal/crease angle is changing by more than 60 degrees. Thus for smooth surfaces, such as a sphere, no edges will be drawn except at a seam. In this example of a sphere this will result in an arc. In addition, mesh and contour lines may be displayed in conjunction with any surface type including vector.
Outline edges will display only as geometry colored with no mesh or contour overlays and is ignored for integration. It is intended as a visual aid only.
How can I see one boundary that is inside of another?
If there are nested boundaries, transparency can be used to see through the various boundary types. In addition, thresholding can be used to cut away an outer boundary in order to be able to see an inner boundary. Thresholding in X, Y or Z are often good ways to cut away an outer portion of the model. You may also use the outline edge display type for the outer surface. This will enable you to see the inside surface, while just seeing the outline of the outer boundary surface.
When integrating boundary surfaces, take care not to specify redundant faces in the boundary type selection as these faces will register multiple times in the integration calculation.

## Error Conditions

There are no boundary types defined for any datasets

If your data reader did not define any boundary types or you have read in a structured dataset without a structured boundary file, you will not be permitted to create any boundary surfaces.

## Limits

The upper limit for boundary surfaces that can be created on a single dataset is 20,000. The number of boundary types within a single file is also 20,000.