Join Josh Modglin for an in-depth discussion in this video Creating surfaces: Breakline definition, part of AutoCAD Civil 3D Essential Training.
- [Instructor] So far, we've created a surface by adding points using a point group. Those points, of course, were added providing the x, y, and z to create the triangles between the points. What we're going to do now is we're going to try to align those triangles to line up better with our grade breaks and get a more accurate rendering of the existing ground. To do that, let's go ahead and open up our exercise file. It's 03_SurfaceBreaklines. In this drawing, what we've done is we've turned on the TIN, or the triangles, so that they're more visual.
You can see how the surface is created. And so what we have is we have our edge of pavement, our centerline, and then we have a top of slope and bottom of slope on all these ends, on all these three sides here of our intersection. And if you notice, here our triangles go across the edge of our pavement. Really, this is what we would call a grade break. The pavement is going to be flat, and then there will be a change of grade between the pavement and the bottom of the slope.
You additionally see that in a few other locations, such as right through here, with our slope. As well as here, with our sign. So what we're going to do is we're going to add what are called breaklines. So I come to the Surface, Existing Grade, under Definition, we're going to add breaklines. I'm going to right-click, choose Add Breaklines. Now there's a few different types of breaklines you can add. Standard breaklines provide a plane that the triangles can't cross.
And that's great; that's what we're looking for. That's what a breakline is. In addition to providing that plane, the polyline, or whatever breakline object that is used, a 3D polyline, survey figure, something similar, it will also add the x, y, and z coordinates at every vertex of that object selected to the surface definition. And that's not exactly what we are looking for when we're working with survey data. We already have the x, y, and z from the actual survey.
Now, if those x, y, zs line up and are from the survey data, in other words they were shot points, then it's probably okay. But a lot of times, it's probably better to use a proximity breakline. Proximity breakline only adds a grade break. In other words, that line or plane that the triangles can't cross. So that's what we're going to do in this exercise. We're going to choose Proximity, choose Okay. And we're going to select all the different grade break poly lines that we have in the drawing.
And we can just use regular polylines, because the z doesn't matter, because it's not going to add any coordinates. It's simply establishing a plane where the triangles can't cross. So you see this triangle here, this triangle can no longer cross this plane. So I'll go ahead and press Enter, and you see now how the triangles have readjusted, realigned, so as to not cross the edge of pavement. Same with our slopes, we have them lining up better as well.
So you get a much more accurate rendering of the surface by adding grade breaks, or in this case, Civil 3D calls them breaklines.
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.
AutoCAD Civil 3D: Designing Residential Projectswith Eric Chappell3h 11m Intermediate
AutoCAD Civil 3D: Designing Gravity Pipe Systemswith Eric Chappell3h 33m Intermediate
1. What Is Civil 3D?
What is Civil 3D?4m 43s
2. Civil 3D Interface
3. Establishing Existing Conditions
4. Modeling a Surface
5. Layout of Parcels
6. Design Horizontal Geometry: Alignments
7. Designing Vertical Geometry: Profiles
8. Civil 3D Corridors
10. Gravity Pipe Networks
11. Pressure Part Networks
12. Feature Lines
13. Grading Objects
14. Share Your Data
15. Plan Production Tools
- Mark as unwatched
- Mark all as unwatched
Are you sure you want to mark all the videos in this course as unwatched?
This will not affect your course history, your reports, or your certificates of completion for this course.Cancel
Take notes with your new membership!
Type in the entry box, then click Enter to save your note.
1:30Press on any video thumbnail to jump immediately to the timecode shown.
Notes are saved with you account but can also be exported as plain text, MS Word, PDF, Google Doc, or Evernote.