Displaying cut/fill labels

For those of you that don't know who he is, Peter, among other things, is the newest Product Manager for Civil 3D. He has a programming background, and before the recent switch to his current title, was the API Product Manager for Civil 3D. Anyway, he's too smart for his own good sometimes, but it's great for us, because we can reap the rewards.

This tip is solely Peter's doing, and I can neither confirm nor deny any of the credit!

Displaying cut/fill labels with appropriate colors.


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Here is the end result of this tip. Note that the cut volume labels are red, and the fills are green, and they are each inserted on a grid.

Here is how to do it:
1. Create a volume surface that represents the two surfaces you are comparing

2. Create an expression for Surface Spot Elevation labels
- Name it "Negative Value"
- Use this expression; -1 * {Surface Elevation}


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This expression will take a value, and multiply it by negative one, changing a positive integer into a negative one, or for this case, taking a negative and turning it into a positive. The ole double negative trick!

3. Create a new Surface label style for Spot Elevation Called "Cut Fill"

- Rename the label Component to "fill"
- Change its color to Green
- Modify the Surface Elevation label component
- Edit the text component and change the Sign Modifier to "Hide Negative Value"


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4. Make a new component for the Cut value
- Copy the Fill text component
- Rename to Cut
- Change the color to Red
- Edit the Text Component, and replace with the Negative Value expression
- Change the Sign Modifier to "Hide Negative Value"


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Now add Surface labels to the Volume surface on a grid, using the Cut Fill style. All the spot elevation in a cut area (the negative values from the volume surface) will be labeled with the Red label, and all the spot elevations with a fill area (where the volume surface is positive) will label with the green text. Because we chose to hide the negative values, and we used an expression to turn a negative into a positive (the cut), it automatically display the appropriate spot elevation.


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Cut and fill

1. Make sure you have two surfaces created for comparison; i.e. an existing surface and proposed surface in C3D.
2. Next, create a new volume surface. There two methods for volume surface which are TIN volume or GRID volume. Choose either one and select your surfaces appropriately as shown in the diagram below:

3. Notice that when you hover your cursor (crosshair) over your Volume Surface, it will give you a +ve or –ve values depending on whether the area yield cut or fill as shown.

4. Once you have your Volume Surface created, you can begin to generate the Cut and Fill shade. In order to do that, you’ll need to go to the surface properties and choose the Elevation Banding (2D) (provided if you’ve created your drawing via the _Autodesk Civil 3D (Metric) NCS Classic template). Buzz me if you need illumination.

5. Subsequently, go to the Analysis tab. Choose only 2 ranges and click on run analysis. Change the Maximum Elevation values for ID no. 1 to 0 and the Minimum Elevation values for ID no. 2 to 0. 6. Click ok and you’re done. You might observe that at times your surface doesn’t mirror the surface you have in mind. Don’t fret, make use of the edit features under the surface properties i.e.; you can add Boundaries to show only the extent if your working area, cut/fill only…etc.

7. Last but not least, I have some engineers who came to me and ask whether C3D can generate the Cut and Fill shade in hatch pattern instead of hatch solid. Well the there is a workaround. The good thing with C3D is it comes together with AutoCAD and therefore it has the best of both worlds. What you need to do is to export the completed drawing to AutoCAD (File>Export>Export to AutoCAD)

8. Open your drawing using Civil3D as AutoCAD and you’ll notice that the solid hatch representing the cut and fill is not in 1 piece. This is the tedious part. You’ll need then to edit the hatch solid to another hatch pattern of your choice and inherit the properties using Match Properties. It’s not that hard after all…

Happy trying.


Tác giả : Wendy Lim Petaling Jaya, Selangor, Malaysia