Join Josh Modglin for an in-depth discussion in this video Creating a feature line, part of AutoCAD Civil 3D Essential Training.
- [Instructor] So now that we understand what feature lines are and how they interact with one another, how sights play a role with feature lines, let's go ahead and create a feature line in our next exercise here. 12-0-2 Feature Line Create. And in this drawing we see three circles that have been numbered. We're going to use those to draw our feature line. So from the home ribbon create design panel, we have the ability in the middle left, feature line, create feature line.
And so, as we've discussed, it will ask us about which site to put it in. We can create a new site, or we can also place it in no site at all. This one we're going to leave in the Creek site or container. Which style, what to name it. Here's an interesting fact about feature lines: they're one of the few simple 3D objects that you don't have to name. Naming comes into play to make it somewhat unique, but again, remember that feature lines are very advanced. They're 3D polylines on steroids.
Have you ever named your polylines before in a drawing? And since it's not something that we use on a regular basis, the software may need to make it unique, and in that case, we'll let it name it, but otherwise I don't usually name my feature lines. Styles, and for me again, it's a very simple geometry, and so styles don't come into play as much for coloration, or look, or feel, or layers. I'd rather keep it very basic and just color it based upon the layer.
But, we go back to our first exercise, styles do play a role when it comes to priority. So I do place a style on my feature line. Additionally, what layer to place it on? Here again we diverge from the standard that we've seen with all the simple 3D objects. We actually have an option here, versus the settings in our drawing settings. We have the object layer settings section. But we can ignore that and simply tell it to use the correct layer to place the feature line.
Click okay. We did not change anything in this window. And it prompts me at the command line, as well as at my crosshairs, to specifiy a start point. So I'm going to use the object snap for center. Beyond, of course, the x y, it also needs the z. So we can type in an elevation or we can choose to use a surface. It looks and says okay, which surface do you want to use? We're going to use existing grade. We can also make some adjustments relative to the surface elevation.
But we're simply going to use existing grade and click okay. And it says okay. It enters that elevation and prompts us for the next point. But we see and additional prompt here. Instead of just specified point, we could begin to create an arc. We're just going to tell it to go and draw this segment to point two, or circle two. Now that we have a point we're coming from, we're drawing a segment; it now has many more prompts to allow us to get an elevation for this point.
We're going to specify grade and we're going type in negative two. Negative two because the ambient settings tell the software that negative two means negative two percent. So it enters the elevation for this point and proceeds. Now it says specify the next point or, not just arc, but we can continue along this same bearing and just type in a length. We could undo the last segment. So we're seeing additional prompts.
We're just going to draw to the center of three. It asks us for some more information. In this case, we're going to choose surface. You can do that, of course, run the command line, you can type in s u, or if you use dynamic input, choose surface. It says the surface elevation for the surface that you selected to begin with is 7-31-42. Are you okay with that? We're just going to press enter and say yes. Now we see another prompt here. It's not just arc, length, undo, but because we have two segments, we have the ability to create a polygonal shape.
A triangle, or now as we add additional segments, you can make it other types of shapes. What you're really finding or seeing here are pretty much the same prompts you would get if you were creating a polyline. With one exception. Every single time you've defined your x y, it'll also add an additional prompt so as to identify the z for that point. Because of that additional prompt and because the z's are things we may be deriving from other methods or getting from the surface for all of the points.
Really that's how we're going to be grading and working. I find it much easier to simply go through the prompts of a polyline and convert that polyline to a feature line. Let's see how we do that in the next exercise.
This course gets you up and running with AutoCAD Civil 3D. First, instructor Josh Modglin shows how to model a surface, lay out parcels, and design geometry, including the making of horizontal alignments and vertical profiles. Next, Josh demonstrates how to create corridors, cross sections, pipe networks, and pressure networks. Then, he covers working with feature lines and grading objects, and how to share your data. He wraps up by providing an overview of plan production tools.
- Navigating the Civil 3D interface
- Using point groups and description keys
- Importing survey data
- Managing figures
- Creating and analyzing surfaces
- Creating parcels
- Working with alignments
- Working with profiles and profile views
- Working with assemblies and subassemblies
- Creating Basic and Advanced Corridors
- Using an Intersection Object
- Making sample lines, cross sections, and section views
- Creating a pipe network
- Understanding pressure parts
- Creating and editing feature lines
- Creating and editing grading objects
- Sharing and referencing data
Skill Level Beginner
Some of the exercise files do not properly function.
This course was built to work with the latest release of AutoCAD Civil 3D. If you are not running AutoCAD Civil 3D 2018 there are some exercise files that will not work for you.