Technical data

Chapter 5 Working with Surfaces
182
Creating Boundaries to Use in
Surface Generation
Boundaries can help eliminate certain surface editing tasks.
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Boundaries control how the surface TIN lines extend to the
surface’s outer limits.
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Boundaries mask internal areas of the surface to prevent
triangulation from occurring.
For example, if a pond exists on the surface, you can either build the
surface and then delete the triangulation lines that cross the pond, or
you can create a boundary around the pond before building the
surface so that the area of the pond is not triangulated. The same
applies to outer surface boundary lines—you can either delete the TIN
lines that extend beyond the survey limits after you build the surface,
or you can create a boundary around the survey limits before building
the surface to prevent the lines from being created in the first place.
Boundaries can clip the surface lines that cross the boundary, or they
can act like non-destructive breaklines, as shown in the following
illustration.