Point cloud technology has really taken off in these recent years. Especially coupled with drone technology, constructing a point cloud has never been easier. These have a varied range of uses in photogrammetry. Point clouds are used to measure a particular site or whole landscapes and even create 3D textured models. Let’s look at what exactly a point cloud is:
What is a Point Cloud?
A point cloud is thousands of data points floating in space. These points collectively represent an object or a particular space (landscape, room, construction site, etc.). Each one of these 3D points has a set of X, Y, and Z geometric coordinates. Therefore each point is a representation of that corresponding point on the actual object. Point clouds can either be colored or un-colored. The colored point clouds offer an added depth of information. To put it into perspective, point clouds are similar to halftone images or artwork created using pointillism techniques.
Point clouds are easy to make and can be constructed on freely available software. They can store greatly detailed information with ease. Another factor that makes point clouds a highly useful tool is its accuracy. Especially geo-referenced point clouds provide extremely accurate measurements.
For most landscapes, a point cloud is created by stitching together several images to create a high-resolution output. The detail of your point cloud depends on the number of high-resolution images captured by your drone. This is of great use in topographical surveys. For instance, in this case, scientists used drones to create a point cloud of an active volcano to study it better.
How to make a point cloud using drones?
The common method to acquire 3D data points to create a point cloud is using a 3D LiDAR scanner. However, drones have proven to be just as efficient and cost-effective. Thus, to create a point cloud using a drone, capture aerial images of your location. Make sure that the images are of high-resolution and overlap each other by at least 60%.
Finally, you need to load your aerial images on a photogrammetry software for processing. There are several photogrammetry software for this process. We chose WebODM Cloud to create our point cloud. Here is a complete tutorial on how to create a point cloud on WebODM. It’s also relatively simple to convert that point cloud to a textured 3D model. WebODM is an open-source and free photogrammetry software provided that you have the hardware configuration to run it. Instead, hosting WebODM on a cloud server like AWS is more economical and faster. If you want to create seamless point clouds, orthomosaics, and DEMs (Digital Elevation Models) using WebODM, reach out to firstname.lastname@example.org.