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.
Source: Wikipedia
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 webodm@algopixel.tech.
