Point Cloud snapping is a way in point cloud software to interact with the data and allow for horizontal, vertical and depth constraints. Point Clouds are usually images or sequences of images captured by lidar or any other rangefinder from different angles. A Point Cloud from a 3D scanner is a digital 3D model of surfaces found in reality captured by laser pulses traveling from an emitter to a target, but also by radar systems, ultrasound scanners, cameras etc.
Why do you use Point Cloud snapping when using point cloud software?
Point Cloud snapping is a way of making a sequence of point clouds compatible with each other. It ensures that the point cloud data aligns horizontally, vertically and in depth. This can be done by using different types of sensors to gather the information from our environment that we call Point Clouds. In reality one doesn’t get perfectly horizontal surfaces or points at exactly right angles to each other, this is why Point Cloud snapping provides tools for compensating errors caused by imprecision in laser scanners and rangefinders used to measure these 3D coordinates. The best way to use the Point Cloud snapping is when you scan an object in several passes with different accuracy levels or in case you need higher positioning accuracy than your scanner supports natively. Doing so will lead to a much better accuracy of the resulting point cloud.
How does this work?
Point Cloud snapping is done by different sensors, most commonly it is LiDAR but also radar systems are used for this purpose. The data is stored in the cloud and ready to be processed. You can use point cloud software programs to convert it into a 3D model that you can visualise, print or manipulate with other software packages.
Point Cloud snapping differs from sensor to sensor so one has to ensure that the algorithm used in the process of generating the point clouds precisely matches each other in order for them not to deviate later when being brought together for further processing. The accuracy of these measurements are usually expressed as an error margin which tells how close two surfaces must be for this snap-to function to work well by excluding minor deviations caused by imprecision during scanning along x, y and z axis. The important thing here is that there are factors that can affect this accuracy, such as the quality of the sensor, but also how it is used.
What can I use Point Cloud snapping for?
Point Cloud snapping can be used to align point clouds that have been scanned from different angles and were gathered by a scanner or a rangefinder with different accuracies or resolutions. This way one ensures that the measurements are compatible with each other and work well together when further processing these cloud data using common software tools for 3D model generation. Picking another type of point cloud, you could use it to check if the walls in your house are perfectly vertical or horizontal which helps you to make them straight without compromising their stability. In case you want to check whether two scanned objects fit into each other perfectly or just need a quick idea how they will look, point cloud snapping is the way to go.
