Understanding where point clouds come from - Revit Tutorial

- [Narrator] The model that we see in this view is actually not a model. All that we're looking at is inside of Revit is laser scan data. If we would zoom in by just clicking inside of the view and then spinning the wheel of a mouse you'll notice that as we get closer we'll begin to see individual dots. What occurs during a laser scan is that the laser scanner will shoot a laser and each one of these points is another scan point, meaning that the laser has hit a surface and then has bounced back to the laser scanner in order to create the laser scan that you're looking at currently. Obviously if you zoom in really tight all you see is just a bunch of dots. Also, if you move into an area and in this case I'm just holding down my mouse and panning over and then spinning in, you'll begin to think that you're kind of looking at a cloudy object. These laser scans, what they produce is called a point cloud, because you have individual points, which make a kind of cloudy looking object if you zoom in on them. If you zoom out, you can begin to see all those little details that you were missing when you were zoomed in on that point cloud. Now there's different kinds of quality of laser scans. If I spin the wheel of my mouse and then zoom in here on the pipe, we can tell that there's some sort of pipe or duct there on the back on the air handling unit. Unfortunately the quality isn't quite good enough for us to tell exactly what's going on where we have this elbow, which is making the turn here, attaching to a pipe, which is going into the back of the air handling unit. On the other hand, we have a fairly great level of detail on the ladder itself and really, if we wanted to model near the ladder, or get the exact dimensions of the air handling unit, which shows up right here, we could, because there's enough detail there that we could model those out. On the other hand, if we spun the point cloud around by just clicking on a corner of what's called the view cube, which is up here in the upper right-hand corner, then zoom in toward this back section just by spinning the wheel of a mouse, you'll start to see that there's big chunks missing. Why are those chunks missing? Because they didn't show up in the laser scan. We weren't able to get the actual laser scanner back into that corner to pick up all the detail that shows up right here in this location. So whenever you're modeling it against a laser scan, you'll only be able to model up to a point where your laser scan data is good. If you don't have enough laser scan data, you won't be able to model those areas where your laser scan wasn't able to shoot its laser and then have the light bounce back to the laser scanner. In case you're wondering what a laser scanner actually looks like, I can show you that. I'm going to minimize my screen and this is actually an image on me giving a presentation on using a laser scanner. I'm showing a point cloud here in the iPad that I'm holding and this is a laser scanner that we have here in the background. The laser scanner can move up to look up, move down to look down. It can spin around in order to take pictures going all the way around and to collect those points going all the way around. Different kinds of laser scanners have different qualities meaning that some laser scanners can get points very far into the distance, several hundred feet away. Other laser scanners can only get objects which are close by. Most laser scanners are capable of taking pictures. Some will even help with he assigning of colors to the individual dots that we see in the laser scan to better identify what each one of those objects actually are. So the thing to remember about a laser scan is that if you want to model against your laser scan date like we'll be doing in this course, you need to make sure that you have a good, quality laser scan. As we go along the course there'll be certain things that we model and we can model them because we have good quality of the scan of that information. There'll be other areas where we're just guessing as to what the object is. There'll be other areas that we can't model at all because we just don't have enough quality in the laser scan to be able to do an appropriate model in those areas. Now that's not necessarily a problem of the laser scanner itself, it's more of a problem of the fact that we didn't get enough laser scan points in this laser scan model that we'll be inserting in to be able to model everything, but what we will be able to do is model such things as duct, or pipe, or floors, or walls and a wide variety of different things. And the processes that we learn along the way can be applied to all the other objects in a Revit environment. So let's get started using your Revit skills to model against a point cloud.