A grading object has its own properties and behavior, like other object types in AutoCAD Civil 3D.
A grading normally consists of a face bounded by a base line, a target line, and several projection lines. The base line can be any open or closed figure from which you want to project the grading. It can be a feature line or a lot line. A feature line is any linear feature in the drawing, such as a ridge line, building footprint, or the bottom of a swale. The target for the grading can be a surface, a distance, or an elevation (absolute or relative).
Line components of a grading object
Before you start grading, you must configure settings and establish criteria such as the following:
- Grading site: Gradings are created in a site topology. If you do not want a grading to interact with other objects in a site, create a new site for your grading objects.
- Grading group: Grading objects in a grading group are consolidated to create one grading group surface so you can compute volumes. Before you create gradings, decide how you want to manage them with regard to surface creation and volume computations.
After you create a grading group, volume tools within AutoCAD Civil 3D show you the amount of cut and fill required for the grading design. You can raise or lower the grading group incrementally to adjust volume requirements. You can also change the elevation of points along a grading base line, change the grade of a base line, or modify the grading criteria.
Grading criteria specifies the grading method
- Grading footprints: Grading objects are projected toward their target from a selected footprint. Footprints can be feature lines that you create specifically for this purpose, or you can export corridor feature lines or use parcel lot lines.
- Grading targets: Grading objects require a target. This can be a surface, a distance, or an elevation.
- Grading criteria: When you start grading, you specify grading criteria . This is how many of the grading settings, such as grading target, are specified.
The list of grading objects defined in the drawing appears in Toolspace, within the Sites collection on the Prospector tab.
Grading styles and Grading Criteria Sets appear in Toolspace on the Settings tab.
Topics in this section
- Parts of a Grading Object
A grading object normally consists of the footprint, the daylight line, the projection lines, and the face.
- Grading Regions
You define grading regions where a grading object requires different criteria along different parts of the footprint.
- Grading and Surfaces
Grading groups can be automatically turned into surfaces that dynamically update when you edit the grading. You can also create a detached surface from a grading group, which is no longer associated with the gradings and does not update when you edit the grading.
- Feature Lines Collection (Prospector Tab)
Use the Feature Lines collection in the Prospector tree to manage feature line styles and layers. You can also view feature line information, such as length, elevation, and grade.
- Grading Groups Collection (Prospector Tab)
As you create each grading group , they are displayed in the Grading Groups collection on the Prospector tab in Toolspace.
- Grading Collection (Settings Tab)
Use the Grading collection in the Settings tree to manage grading settings, grading styles, grading criteria sets, and grading command settings.