5 Points About Point Clouds
As the use of 3D laser scanning technology gains popularity, more architects are learning to incorporate point cloud data into their workflows. So to help ensure you understand point clouds and how to use them, here are five important lessons.
1. What is a Point Cloud?
A point cloud is a data set comprised of points in space, with each point identifiable by its position as an X, Y, and Z coordinate. The point cloud can contain millions or even billions of points. When seen together, these points can create a detailed, accurate model of an object or surface that is scanned, even measuring and replicating exact size and shape across distances.
The number of points, which constitutes the density of the cloud, can vary greatly depending on the intended use of the point cloud model. Because point clouds can range in size, scope, and density, point cloud models can serve a number of functions and be used in a variety of fields for obtaining measurements and creating models.
2. How is a Point Cloud Created?
According to Point Cloud Library, an open-source point cloud processing software, “Point clouds can be acquired from hardware sensors such as stereo cameras, 3D scanners, or time-of-flight cameras, or generated from a computer program synthetically.” Stereo cameras are cameras that capture 3D images through the use of multiple lenses. Each lens has separate image sensors, which means that the camera can take two or more photographs at the same time and layer them to create 3D images, much like how we process depth through binocular vision. Point clouds are generated by digitally measuring the depth, which is indicated by the disparity in various points between the two images.
Time-of-flight cameras capture 3D images and record the reflected light based on the time it takes for a light signal to bounce off an object, similar to 3D laser scanning.
Perhaps the most common method of creating point clouds is with 3D laser scanners. A 3D laser scanner is a non-invasive tool that measures complex, detailed surfaces by passing a laser light across the surface of a subject. The surface reflects the laser back to the scanner, and the scanner records this data as a point. More advanced scanners may also have camera functionality that assigns color values to points. The result of a 3D laser scan is a highly detailed, accurate model of the subject.
Some objects or spaces might be too big or detailed to capture in just one pass of the scanner; in these cases, the scanner can take measurements at multiple different positions within an area, and the resulting scans can be stitched together digitally to make one complete model.
3. How Should I Use a Point Cloud?
Architects, landscape professionals, and entertainment designers can use 3D scanners and point cloud data to model a pre-existing space. Whether you need to model a particularly odd terrain or need to work with an existing building, the point cloud model will allow you to accurately measure these surfaces and design to fit the space.
It is important to note, however, that point cloud data cannot be used directly. When you export the point cloud data from the scanner, it will not automatically be a usable, triangulated mesh; it will still be just a field of dots in space. Though many scanning services offer to create workable models from point clouds, you can also use 2D/3D design software, like Vectorworks, to import and trace over the point cloud for your model.
4. When Should I Incorporate Point Cloud Data into my Workflow?
Whether you will create a point cloud model for a design project is up to your discretion. If you need to work within a pre-existing space and the area is complicated to work with using traditional methods of measurements or a floor plan, then you might consider renting a 3D laser scanner or hiring a scanning firm to help you map out the area. A point cloud model will ensure that the data you obtain from an area is accurate.
Scanning can be pricey depending on the size of the area, the quality of the point cloud, and the length of time it takes a crew to scan the area. While the price of 3D laser scanning may decrease as the technology improves, it will likely be too costly to use on every project; you might consider creating point clouds only for your larger, more complex design projects.
5. How Can I Use a Point Cloud in Vectorworks Software?
In their webinar “From Point Cloud to Documentation,” Vectorworks Senior Architecture Product Specialist Luis Ruiz and Software Engineer Fahad Zafar walk through the process of modeling an area from point cloud data, from selecting a file type and creating a point cloud to importing data into the software and modeling over the point cloud data. In the webinar, Ruiz demonstrates simple techniques to create a usable, accurate model of a famous pre-existing space, the atrium of the Philadelphia Museum of Art. Watch the webinar to see how easy it is to work with a point cloud in Vectorworks software.
Have you used point cloud technology in your designs? We would love to see it! Send your project to firstname.lastname@example.org for a chance to get it featured.
And if you want to learn more about how point clouds can transform your workflow, visit the Vectorworks community boards to get tips from other users.