Use the Prospector tree to add boundaries to a surface.
When you add or remove boundaries, the surface is modified and the modification is added to the definition list for the surface.
Surface boundaries are defined from closed polygons, such as a closed polyline or a parcel, or from surfaces. Surfaces may be selected as boundaries when the Hide boundary type and the Non-destructive breakline options are both selected.
The following illustration shows an example of using a corridor surface as a hide boundary for the existing ground surface:
Areas hidden by boundaries are not included in calculations, such as total area and volume.
When creating a boundary, you set arc tessellation and specify whether the boundary uses non-destructive breaklines.
When you use polygons/polylines that contain curves for boundaries or breaklines, set the mid-ordinate distance of the chord segments, which is used to tessellate the arc segments of the boundary polygon/polyline:
Specify whether a boundary uses non-destructive breaklines when you create it by selecting Non-destructive breaklines in the Add Boundaries dialog box.
When you create a boundary with non-destructive breaklines along the edges of the boundary, the triangle edges are clipped exactly where they cross the boundary:
If you create a boundary without non-destructive breaklines along the boundary edges, only triangles that are completely within or outside the boundary are affected:
Tutorial Exercise: Adding an Outer Boundary to a Surface
Tutorial Exercise: Adding a Hide Boundary to a Surface
To add boundaries to a surface
- In Toolspace, on the Prospector tab, expand the surface Definition collection, right-click
, and click Add. - In the Add Boundaries dialog box, enter the boundary name in the Name field.
- Select the boundary type from the Type list. See Boundaries.
- Optionally, select Non-destructive breakline to specify that the boundary uses non-destructive breaklines.
- Optionally, if the polygon from which you are creating a boundary has curves, either enter a value in the Mid-Ordinate Distance field or click
to specify a distance in the drawing area. - Click OK.
- Do one of the following:
- Select one of the following to define the boundary:
- An existing polyline
- An existing polygon, such as a circle object
- An existing parcel
- If you are defining a hide boundary and the option to use non-destructive breaklines was selected, you can enter S for Surface and select an existing surface in the drawing.
- Select one of the following to define the boundary:
The boundary is created and added to the surface Boundaries collection in the Prospector tree.
