Modeling steel shapes on a point cloud can be difficult. Learn how to use the Fit Beam feature to determine the steel shape, size, and position.
- [Instructor] Fitting steel is a little different than fitting piping, but the principles are much the same. Because the profile of the steel shapes are different to the piping, the pattern recognition is a little bit more complex. With piping we're looking at cylindrical shapes so the way the laser bounces off the curve shapes makes it easy to determine the diameter. With steel it's a little bit different. The web and the flanges make hard shadows where the laser can't always detect the full shape of the steel and in addition, steel typically has other items attached to it like connection plates and bolts.
Choosing the best place to select your points on the steel beam is important to make sure you get a good return. Now we're going to take a look at the steel that makes up these small piping skids. So I've gone and clipped these out of the point cloud and I've changed the color to white so that we can see them a little better, they're very dark against the black background. So using what we learned in the last video, we're going to run to the Fit beam command, so this is in our As-Built Plant. We're going to come to the Beams panel and we're going to choose Fit beam.
Now as we said before, we're going to use Detect Type and we pick two points on a plane. So if we pick two points on the web or two points on the flange, it doesn't matter which as long as it's the same plane. So let's come down to this area here and I'm going to pick two points and let's see what happens. Now this is a dialog box that we get. I'm going to show you the graphic here. You can see on the screen we have the shape of the steel and we have this green section here.
Now, this is the cross-section. Now, the exact location of this green plane here is the cross-section that we're seeing in the points in the Fit window. So a couple of things we can do here. We're going to adjust what we see in this window and then see how it fits against the points so we have a visual check as well. First of all, let's go look at our shapes here. Now we can see we've got deflection. So when the laser beam passes over something that's got a sharp edge, it trails a little bit so you almost get that sort of diagonal deflection.
And you can see that right here, there's a diagonal line. So the shape that the algorithm is returning is clearly not the right shape, we can tell by looking at it here and we can tell by looking at it here. It analyzes the shape of the points at that cross-section and then tries to compare them and fit them to the closest match of the steel profiles in the catalog. So it's returning a W8x48 and we know that's not right. So let's come in and just holding your mouse button down, let's just delete some of these deflection points.
You'll see they're usually just straight points. And when you're ready, anytime you make any changes, you'll see the background turns red. That means that you need to recalculate. So I'm going to come up and recalculate. And you'll see it's found the correct steel shape this time. So we've got point coverage along that surface. The dark line is the plane that we picked so we know we're oriented the right way. You want to make sure that we've got that radius in there as well. So now that we're looking a W8x18, we can do a visual check here and see that that looks good.
So if that's what I want, I'm going to say insert beam of this type. Now it's placed the section of beam just between the two points that I picked. I can manually come down and extend that if I want. I can choose the Extend command from the command line. And just pick two points and have the steel extend out to these two points. When I'm done, I'll just say Finish and I can finish again and there's my steel beam.
Now if we rotate around there, you'll see that there's points and solid. That's what you wanted to show that you've got a good fit here. So we can run that again. I'm going to Detect Type and I'm going to pick this beam right here, so two points on the beam. And again, just based on the points. Now if I'm not getting a great fit this way, W8x48 doesn't look right to me. The other option I've got is I can use this slider and you can see as I slide that position along, you can see the slider move on the actual point cloud itself.
As I slide that you see the cross-section of points change and some areas are little more fuzzy than others. But you can move that into an area where there's not a lot of deflection or straight points. For example, this looks a little better. There's a couple of points right out here. A little bit of deflection, again, just going to clean that deflection up and recalculate. If it's still not finding the beam you can always do a visual check. So we can see here that the radiuses are correct. It's the actual size of the beam, so what we can always do is just visually go through the list, so it's returning a W8x48.
Now as I move down this list you'll see, not only does it change inside the window here, but it changes on the point cloud as well until you find the shape that looks like it fits best. And there it is, there's the shape again. And if we look at the size, it's a W8x18. So I'm going to say just insert this beam again. Now I again, can come and manually extend that down. And I can take it right up to the end and finish that. But again, extra steps that we don't need. So, now we've got those two beams in, I'm going to close.
And when fitting steel beams, the web and flanges make hard shadows where the laser can't always detect the full shape of the steel. In addition, steel typically has other items attached to it like connection plates and bolts. So choosing the best place to select your points on the steel beam is the key to making sure that you get a good fit.
- Importing ReCap data
- Creating a VirtuSurv project
- Setting point-cloud parameters
- Loading specs for pattern recognition
- Creating and saving sections and slices
- Viewing points with the Scan Navigation feature
- Fitting linework and shapes to point-cloud data
- Editing drawing data
- Analyzing drawing data
- Sending coordinates to AutoCAD with VirtuSurv
- Modeling objects with VirtuSurv macros
- Processes for piping and steel beams
- Creating floor plans with the As-Built building tools