Join Paul F. Aubin for an in-depth discussion in this video Link a point cloud to Revit, part of Revit: Tips, Tricks, and Troubleshooting.
- [Narrator] Field surveying and capturing existing conditions has come a long way in recent years, and many firms are now relying on LiDAR, or laser scanning, to actually capture point clouds of their existing conditions. So a point cloud is quite literally a collection of thousands if not millions of points that are captured from a laser scanner. So the laser scanner shoots lasers in all directions, and it records the distances to the bounce back of every one of the laser beams that it fires and it records all of those as a series of points, and then that gets compiled into a file called a point cloud.
So what I want to talk about here is how we would take that point cloud file and bring it into Revit to use as the basis for the existing conditions in a Revit project. Now you don't have to be in any particular project for this example, so I've just created a brand new project from the out of the box template. I'm going to go to the insert tab and click on the point cloud button here and I've provided a few sample point clouds and they do come in different file types, but the default type that Revit is looking for is a RCP file.
That's the Autodesk format for point clouds. It's the recap file format. So I've got one of those right here. Now I'm going to go ahead and accept the default positioning of center to center, but there are some other options, like origin to origin, and shared coordinates. But let me talk about what center to center does. Notice that when it comes in we see kind of this like little square shape right there, but if we open up the south elevation and take a look, and I'm going to just zoom in slightly here so that we can see the point cloud, notice that center to center is quite literally center in all directions.
So it wasn't just the center in plan, it's actually the center in 3D. So you can see that my point cloud is significantly lower than level one. So I can just simply move it. So I'm going to select the point cloud, go to my move tool, and notice that as you move around in the point cloud all of those millions of points are actually snap-able. So it can get a little overwhelming at first, because you're not really sure what it's snapping to, but you should be able to find a point down at the bottom there, kind of where the floor is, click there, and then I'm going to move it straight up and snap it to level one, okay.
Now when I go back to level one, remember that earlier this portion of the point cloud was what was intersecting level one and we were seeing a little square. Now when I go back to level one notice that I'm getting a much larger square. So earlier we were cutting through this upper light well area that goes above these columns. Now we're cutting through the entire courtyard and we're seeing a much bigger space. So that's a really important thing to understand about the way that Revit treats point clouds. All of the settings of the view will apply here.
So in this case, I'm in a floor plan view, with a certain view range, and it's slicing through and showing me just that portion of the point cloud. If I create a section, and I'll just kind of make this section match roughly the angle of the point cloud, now notice that it's just defaulting back, you know, a short distance here. Let's open up that section, and when we take a look at the point cloud in this view, notice that inside the archways it's not showing us any points, because we're only doing a thin little slice through the point cloud in this case.
But if I go back to level one and stretch this back to here, and then reopen the section, now what you're going to see is all of the points off in the distance are displaying as well. Now, the next thing I'd like to talk about is notice that we can actually see the tripod right here of the scanner, okay. So what that's telling us is if we go back to level one here, there it is right there. It's a little bit easier to see. What that's telling us is that we have more than one scan here. So often when you want to capture a point cloud, you need to put the scanner in more than one location, because imagine that the scanner is sitting right here, and it's shooting the lasers off in this direction.
This object right here, this cistern object, would block many of those laser beams from getting to the back wall, as would any of these columns, or any other element that happens to be in the foreground. So if you want to do a full capture of a space, you actually have to put the scanner in several locations, because it's a line of sight technology, and so often your point cloud will contain multiple locations. Now you can actually access those locations if they're saved with the point cloud file. So I'm going to show you that right now. Okay, so let me just kind of move this over here, and then I'll do visibility graphics, and I'm going to type VG, and notice that there's a point cloud tab.
Each point cloud will be listed here that you've linked in, and then if you expand it, that point cloud may have scan locations. So let's expand again, and this particular point cloud actually has five scan locations. So what's interesting about this is you could hide or show individual scan locations. So I don't really know where that one is, but I just sort of turned it off, and you saw some of the points disappear. If I turn it back on some of those points reappear. Another way that you can identify the individual scan locations is to select it and apply an override.
So I could override it to a single color, and when I click apply, now any of the points that were captured by that scan location are changing to this red color, and you could actually do that for each of the scan locations if you wanted to. Now, the only option you can get for the individual scan locations is the single color override, but if you go back to the point cloud itself, the default behavior here is RGB mode, but if I click on that there are other display modes that are available here as well.
Now some of these will be more visible in plan view than others, so for example, if I did the elevation option, that's going to do a gradient from blue to red. You can change those colors if you want, but if I apply that, you know, everything is going to turn blue except for that one scan location that I applied the override to, okay. So, just to avoid confusion, let's remove that override, and then click apply again. So you see how everything turns blue. So that's not really terribly useful.
Well, the reason for that is the scanner was down at the floor, so the points that are closer to that elevation are going to be in the blue color, and the points that are further away are going to gradiate to the red. So a better way to see that would be to look at it in our section view. So I'm going to go back to the section view here, and zoom out a little bit. Let's push it over here. Let's do visibility graphics, go to point clouds, select the point cloud, and click on the RGB mode and change it to elevation like we did a moment ago, and now you can kind of see the difference, right? So you see how the points that are down low at the low elevation are blue, all the way to the points that are up at the highest elevation change to red, okay.
There are other display modes here as well. We have the intensity which changes it to a black and white display. So intensity here quite literally talks about the intensity of the laser beam, okay. So the further that laser beam travels when it bounces back it loses some of that intensity. So this is another way of thinking about distance, right? So the points that are really close to the scanner are going to be brighter because there's more of them, and they're more intense than the ones that are further away and more scattered and dispersed. So it's just a way of visually understanding your point cloud.
So once again you have elevation, you have intensity. You could force the whole thing to a single color, or you could even go to this mode here, which is normal display, which would show the information based on, again, whether or not it's directly facing the scanner or not, or if it's off in a skewed angle, and so on. I'm going to set this back to, to RGB. Now the other option that we have here is the scan regions. Now not every point cloud will have scan regions but it really just depends on the file format, and who created the point cloud.
But I've actually included a couple scan regions here, just for us to look at. So for example, I've got one called light well, which is all the points up here. So if I turn that off and click apply, all those points disappear. Now that might be easier to see in a 3D view. So if we're looking at the 3D right here, some of those points might be a little distracting. But if I go to VG, and I turn off that light well again, and click apply, now we can see down into the courtyard space, you know, from this scan vantage point.
So, you could see that it's pretty important to set up some views both the cut range of the view and the visibility graphics of the view, but set up some views that show you the point cloud in the most favorable way, because, you know, when you zoom in on this, this surface of the wall, that wall wasn't perfectly smooth. So as you can see, it kind of looks like a thick line there, but what that really is is just a lot of points all kind of at slightly different distances, and, you know, you could take measurements off of these points here, and Revit will try to sense where they all kind of find a line.
So you could see it's pretty easy to find that virtual line along there, but those points are not all in the same plane. Likewise, you could trace over this, you know, with Revit geometry, and again, it will do its best to try and find that geometry for you. Now there is no auto convert. You're not going to just push a button and turn a point cloud into Revit geometry. So this is why it's so important to set up the views carefully so that when you are tracing over that point cloud it's giving you meaningful results, and you're getting an existing conditions model that actually matches what the point cloud told you, okay.
So all of that is possible by the way that you set up the different views. Now I'm going to zoom out a little bit here, and I'm actually going to take this point cloud and delete it, and let me get rid of this wall as well. Let me bring in one other one, because I want to show you what happens if you bring in a point cloud of a different file format. So I'm going to go to insert point cloud and change the files and format here to RAW formats. Now, there's lots of RAW formats. It depends on the scanner manufacturer which format you'll get, and I've got one here that's in the PTS format.
Now, when you open up a non Autodesk format, it will tell you that it needs to index the file, okay. So this is kind of like optimizing the file, you know, you've got millions of points, and it kind of creates an index of all those points, to make it a little easier to work with. So, if I say yes here, it says it's going to take some time to do that. You have to answer some questions about the file coming in, you know, what units it is, and so forth. I'll just accept all the defaults here, and click start indexing. Now again, this could take a while. It even warned you as such, so it's a good idea to kind of step away for a little while, and come back when the process is finished.
So when the progress is done, you just click close, and that actually created an RCP file. So then you would go back to point cloud, and change it back to RCP file and you'd see the file listed right there and you could continue with linking it in, just like we did before.
NOTE: The exercise files for this course can only be opened in the most recent version of Revit (Revit 2017).
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