What is a Point Cloud?
Many new to laser scanning are unsure of what a point cloud is and why the process of importing is needed. Scanned information cannot be directly imported to CAD software a definition of the point cloud will clarify this issue.
It takes three steps to get a site from scan to model.
- 1. Scan the area with a FARO laser scanner
- 2. Import the point cloud into modelling software to visualize the area. The software lets you visualize and model the point cloud, which at that stage looks rather like a pixelated, digital version of your site.
- 3. Export the point cloud and import it into a CAD/BIM system
Many new to laser scanning are unsure of what a point cloud is and why the process of importing is needed. Scanned information cannot be directly imported to CAD software. a definition of the point cloud will clarify this issue.
What is a point cloud?
Point-Clouds and Real Clouds
A cloud is a 3D mass made up of small droplets, crystals, water, or various chemicals. In the same way, a point cloud is a huge number of tiny data points that exist in three dimensions. If those points were projected out of a scanner they would appear as a cloud that could be walked through.
Therefore, the point cloud that the laser scanner captures is an accurate representation of an as-built object or space. It is saved in the form of a very large number of points that cover surfaces of an object. A point cloud defines a space by recording the points that cover the surfaces within that space.
A point cloud can be explained in an abstract way: Paintings created through pointillism, a technique in which the artist applies a pattern of small, distinct dots of colour applied to a canvas, eventually creating an image. If one were to take a closer look at the painting, one would see every “point” conclusively making up “pointillism.” The same goes for a point cloud. The “point” here is many tiny dots (points) create a whole. The image is made of individual points.
Clouds Make a Whole
Scans need to be taken from multiple locations to get a complete view of the target area. Once imported into the software, the point cloud can be analysed, manipulated, and modified to suit a user’s needs. It also provides point cloud data management, analysis, and advanced modelling.
To work with the information as a CAD model, the point cloud is exported from the software and imported into a CAD modelling program where the data is turned into 3D solids and surfaces. In the past, point clouds were too big to import directly into 3D modelling software. Today’s CAD software, however, can handle very large data sets.
While construction companies may realize the value 3D laser scanners have in creating CAD or Revit models they can work with, employees may not realize the vital second step in getting from scan to model: the point cloud. But the next time they’re looking to create an estimate on an existing project for which no blueprints exist, they could very well thank the clouds.
