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Table Of Contents

Grading Object Usage Tips

elevation target and set the relative elevation to zero, or use a distance target

and set the distance to zero.

Unexpected Projections

When the object has unexpected projections: The combination of numerous

vertices, slopes and/or targets may create a situation that is too difficult to

resolve. In these situations, try to analyze for conditions that would normally

have no solution.

Remember that each vertex with a deflection angle is treated as a corner, and

multiple overlapping corner treatments will not be solved for. It may be

necessary to define a void region for the problem area, and grade that area by

hand. 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.

Volumes from a Grading Object

Volumes from a grading object are for quick reference only: When volumes

are calculated from the grading object, a temporary TIN is created from the

object, and volumes are generated by comparing this TIN with the target used

to create the object.

Because there is the potential that this temporary surface may not match your

requirements, it is highly recommended that you verify critical volumes by

creating a TIN from the object and verifying that this TIN is accurate (ie, create

contours and visually review the TIN). You should then calculate volumes using

the other volume methods available within the Terrain menu.

Grouping Grading Objects

The AutoCAD group command can be applied to a collection of objects:

You can use the Group command to define a collection of grading objects as a

group. Selecting one of the objects within a group will select all of the items

within the group. You can use AutoCAD commands to edit a group of grading

objects, and the Ctrl + and Ctrl - to adjust the footprint elevations of a group of

grading objects.

Note that you cannot edit the properties of the grouped grading objects; you are

limited to changing the properties of one grading object at a time.

For more information about the Group command, see the AutoCAD Land

Development Desktop online Help.

Avoid Using Running Object Snaps When Graphically Editing

the Grading Object

Because the grading object vertex grip points and the grading object itself are

sensitive to elevation changes, it strongly recommended that you turn off

running Object snaps prior to graphically editing the object. This will prevent

the likelihood of inadvertently snapping to the wrong elevation and causing

undesirable results.