Discover how to edit and analyze a surface in a 3D space. The article guides you through removing unnecessary data, rebuilding surfaces, and managing the hierarchy of operations to create an accurate surface model.
Key Insights
- The article highlights the importance of removing unnecessary data from your surface, ensuring the accuracy of your model. For instance, it explains how to remove flat areas and incorrect lines from the model using various tools and commands.
- Rebuilding the surface is key to achieving accurate results. This process involves setting a maximum triangle length and allowing the software to rebuild the model based on the data input. The sequence of operations matters significantly during this process, as the software reads the operations from top to bottom.
- Lastly, the article emphasizes the significance of managing the hierarchy of operations. This involves adding surfaces together in the order of their creation or how they would be built in the field, ensuring the accuracy of the final model.
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In this video, we're going to go ahead and start editing our surface. So what you'll notice in the surface is that there are some triangulation lines that are spanning across different areas where we might not want that information.
More specifically, we're talking about some of these areas that are outside of where our survey was done. So right here, right here, and right in here. We don't have any points in this area, yet we have a surface that spans across these areas.
And you can see this if you select your surface and select Object Viewer. When I select Object Viewer, I get my Object Viewer window and I can analyze what my surface looks like in three-dimensional space. So I'm just clicking and dragging to rotate and reorient my surface.
And so we can see these flat areas that are created in the surface. So right here, right here, and right here. These areas don't have any data to them.
They're basically only lines that are being connected between one edge of our slope here and another edge of our slope here. And so what we need to do is go ahead and remove this data from our surface. There's also some other artifacting that's happening inside of this, and it's easily located along the edges of the street here.
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If I zoom into the edge of my street here, what you're going to notice is that there are some TIN lines that were drawn from my top of curb across to the top of my slope over here. So I have a line that goes from the top of curb all the way over to here, which is not correct. Obviously, I don't have a street that has a vertical face at the edge of it.
It happens because you have these issues when you get to the outer edges of your boundaries or the outer edges of your survey data. So what I'm going to go ahead and do is I'm going to do two different kinds of edits to clean up what our surface looks like. So I'm going to go ahead and close this Object Viewer, and I'm going to do the first edit, which is going into my surface right here, my Full Development surface.
I'm going to right-click and go to Surface Properties. Inside Surface Properties, if you go to the Definition tab, there's information on how the surface is being built. And so if I go to Build and I expand and scroll down inside of the Build dropdown, there should be an option here for triangulation lengths.
So use maximum angle. We also have use maximum triangle length. And so currently, it's set to no for use maximum triangle length.
So Civil 3D will create triangle lines of any length between data points. If you change this to yes, and you set a maximum triangle length of 50 feet, let's say, and I hit Apply, Civil 3D is going to ask me to rebuild my surface. And that's okay, because Civil 3D is going to rebuild everything that we've done.
We'll go over the build operation after I click Rebuild Surface, but it will rebuild the surface and it will remove any TIN lines that are longer than 50 feet. So I'm going to go ahead and click Rebuild Surface. And so what you'll notice is we lost a lot of data up in this area up here.
So maybe 50 feet is being a little bit too safe. We've lost some of the data in this area over here and up here. I'm going to go ahead and actually change this to 100 and hit Apply and Rebuild Surface.
And so we've gained back some of this data. It might not be the best, and we can go ahead and go back and do some edits to this other data that we wanted to get rid of. But for now, let's leave this at 100.
When I talked about rebuilding the surface, what Civil 3D is doing is it's working through a layer of operations to rebuild that surface based on the data that we've put in. And so the data that we've put into the surface is our point group for ground shots, our point group for found points, and then our break lines. And so what Civil 3D does is it looks at our definitions up here, and then it rebuilds based on our operations down here.
So Civil 3D builds the surface in a hierarchy of operations. So it reads from the top down. What it will do is it will add in the point group's ground shots, then it will add in the point group's found points, and then it will add in the break lines that we added to the surface.
Now, if you change the order of this, you can change how your surface is built. And this becomes a big deal when you start doing edits of adding surfaces together, pasting them together to create a combination surface. We are not going to get into creating combination surfaces in this course.
We'll do that when we get to a course that has our grading groups in it and creating surfaces from those grading groups, or when we're creating corridors and creating surfaces from those corridors. But what you need to know is that if you have two surfaces being pasted together, the order in which those surfaces are pasted together matters. So what you want to do when you're pasting surfaces together is that you want to add them in the operations of how something would be built in the field.
If you have a surface, you want to start with your topo (topographic) surface. And then if you have a phase one grading surface that you've created, then you paste in phase one, then you would paste in phase two, and then you would paste in phase three. So based on how you would do the order of work out in the field, you would actually model the surface in the order of work that you would be doing in the field.
So I'm going to go ahead and click Apply and click OK to accept our changes that we made to the surface. Now, if you had an actual survey, rather than the points that we've brought in from this mock survey, your surveyor would hopefully have grabbed some points outside of your parcels here. We don't have that data, so we're going to have to live without having some information in here and some information in the tops.
But if I select my surface now and I go to Object Viewer, what you're going to notice is that when I rotate this back out into a three-dimensional view, a lot of the flat areas in this space are missing because of that maximum triangle length. Now, there is still some, and so that's going to get into our second editing option. We still have flat areas here, flat areas here, and a little flat area over here, and we still have the issues with our street right here.
So I'm going to go ahead and close this out. We have the surface selected, so we have the contextual ribbon bar up, and we're going to be working in this dropdown for Edit Surface. So inside of Edit Surface, we have the options for add, delete, and swap lines or edges.
We have add point, delete point, modify point, and move point. We have minimize flat areas, raise and lower surface, smooth surface, paste surface, and simplify surface. These options, if you remember, are exactly the same as if we went to our definitions, went to edits, and right-clicked.
We have the same exact options here. So depending on if you're working with a surface that's already displayed versus working with a surface you're going to go ahead and do edits and not have it displayed yet, you can go to either option. I'm going to go ahead and go to Edit Surface here, and we're going to delete some of these lines.
So I'm going to go to Delete Line. I'm going to go in and zoom into my area down here. I'm going to drop a window across the lines that I want to delete and hit ENTER.
I'm going to go ahead and move over to here. I'm going to drop a window across some of the lines I want to delete, and hit ENTER. I'm zooming over to here.
I'm finding some lines that I want to delete, and I'm hitting Enter. So as I'm going around here, I'm modifying this surface and removing lines. Now you can do this for a lot of areas and get very, very detailed in your removal, like I'm doing here, or you can accept a little bit of error on the outside edges, knowing that you're not going to be developing in that area.
So I'm deleting out some areas on the outside edges here. The big important ones that I want to remove are these lines that are coming from my street and tying into this top edge up here. So what I want to go ahead and do is drop a window across this area here and delete it out.
And then I want to go over to this side over here. I want to drop a window across these lines here and delete it out. Now, if I hit ENTER one more time, it gets me out of the delete lines command.
I'm going to go ahead and go up to Object Viewer. I'm going to get into my three-dimensional view. And so if I rotate this surface out now and I come down to my street, hopefully those vertical edges are gone now.
And yes, they are. We can see our curb here, our street, our next curb, our sidewalk, and then we'll be going to our surface here or our slope here. We've done a lot of good cleanup here.
So I'm going to go ahead and close this. I'm going to zoom out, press Escape out of selecting my surface, get my surface centered in the window. I'm going to save.
And I'll meet you in the next video where we'll talk about some more editing options for surfaces.
