Breaklines
Breaklines are lines that tell 3D Analyst that
there is a distinct change in slope on either side of the line. They are used
to represent surface formations like ridges, streams, dams, shorelines, and
building footprints.
Top: Simple mass point triangulation does not adequately
model the dam. Bottom: The dam is successfully modeled with breaklines.
Breaklines enforce changes in slope by not
allowing triangles to cross them. Since no triangle can cross a breakline, locations along opposite sides of the breakline belong to different triangles. This guarantees
that they have different slope values, as long as the surface is not perfectly
flat.
Top: Without breaklines, the
triangles cross the ridge of the dam. Bottom: With breaklines
(symbolized in red) along both sides of the the
ridge, the
Breaklines may or may not contain elevation
values. If they do, the vertices will be incorporated into the