2.0

Chapter 1 Using the Grading Commands
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The following illustration shows an arc-line-line interior corner cleanup
condition that is not supported (three adjacent planes are overlapping in
this situation).
Unsupported arc-line-line interior miter corner cleanup
This situation is not supported (three adjacent planes are overlapping).
The grading object cannot clean up the corners in these situations because it
will only calculate cleanup for two adjacent planes. For each segment of the
footprint, a plane at the specified slope is projected to the selected target. This is
true even in situations where slope transitions occur. The interior corner
cleanup method (Concave Miter) finds the intersecting point of two adjacent
planes at the daylight line. It then performs a cleanup by calculating a slope line
from the vertex between the two adjacent segments to the intersecting point.
Due to the complexity of calculating the intersecting point of two or more
non-adjacent planes, cleanup will not occur if non-adjacent planes intersect. If
this situation occurs, you may need to explode the object and manually edit
the areas to produce a terrain model with the desired results. Another option
is to fillet the corner with an arc of sufficient radius prior to creating the
grading object.
For those who would rather not explode the object, you can define a void
region that covers the problem area. To define a void region, use a relative
elevation target and set the relative elevation to zero, or use a distance target
and set the distance to zero. You can then use Daylighting or AutoCAD editing
commands to edit the area and create a TIN from the grading object (as
breaklines). An alternative may also be to manually edit the grading objects TIN
by adding points and lines.