2.0

Table Of Contents
Grading Object Usage Tips
67
Slopes
Vertical Slopes
Vertical slopes are not truly vertical: If two points used in the creation of a
TIN are within 0.0001 drawing units of each other, the Terrain Model Explorer
automatically discards one of the points. Because of this, selecting a vertical
slope for a grading object will always result in a top and bottom point which are
offset slightly (by no more than 0.0002 drawing units) in either the X or Y
direction. This was done to prevent the Terrain Model Explorer from discarding
any of the points in the grading object.
Targets
Grading to a Relative Elevation
Grading to a relative elevation may cause jumps in your daylight line: Due
to the geometry involved in cleaning up corners when footprint segments have
changing elevations and the target is a relative elevation, jumps or dips may
occur. In this situation, it may be necessary to manually edit the daylight line
and projections to achieve the desired results.
Corners
Slope Tags and Target Regions within a Corner Cleanup
Avoid placing slope tags or target region boundaries within a corner cleanup: In
most cases this will result in a partial corner cleanup, or prevent a corner
cleanup from occurring altogether.
Examples of Interior Corner Cleanup Conditions
The grading object cannot solve all interior corner cleanup conditions: The
grading object can resolve most cases of interior corner cleanup. There are
instances, however, where no solution can be found. In these cases, it is best to
rely on the engineers judgement.
To help you understand how and where these instances will occur, its helpful
to understand how in previous releases the Daylighting commands reacted on
interior corners. The following illustration shows the behavior of the
Daylighting commands.
Interior corner results using daylighting commands