Technical data

Chapter 5 Working with Surfaces
180
The following illustration shows a surface triangulation that does not
accurately interpolate the surface elevations, as shown by the cross
sections cut from different locations. By defining breaklines, you can
control how the triangulation will occur with regard to abrupt
changes in the terrain.
You can define three types of breaklines.
■
Proximity breaklines: Defines breaklines using the points in the
database nearest to the breakline that you draw. You do not have to
snap to exact points.
■
Wall breaklines: Defines the elevations of a wall-type object on
both sides of the wall. For example, triangulation is linked to the
bottom of the wall on one side, and then begins again from the top
of the wall on the other side.
■
Standard breaklines: Defines the breaklines using the exact points
or polylines that you select.