Point cloud registration is the process of aligning two or more point clouds to create a unified, comprehensive, and geometrically accurate point cloud.
What is point cloud registration?
Point cloud registration is the process of aligning and merging multiple point clouds into a single, cohesive dataset. These point clouds may originate from photogrammetry or be captured by sensors such as terrestrial laser scanners, often from different positions or angles.
To align point clouds, shared features or common reference elements must be present in the datasets being merged.
How can I register point clouds in PIX4Dmatic?
Before registration, point clouds must be present in the PIX4Dmatic project. These point clouds can originate from:
- Processing a dataset in PIX4Dmatic.
- Importing a point cloud. For detailed instructions on importing point clouds into PIX4Dmatic, please refer to this article.
After processing or importing the point clouds, the next step is to identify the common elements necessary for their registration. These elements are distinct features that appear in both point clouds and are easy to identify. These features must be in the same position in both point clouds, as the software will utilize them as reference points for merging the clouds. Additionally, at least three of these common features must be available to achieve a successful alignment.
This element will be identified as marks (shortcut M). Use this tool to create different markers in all the point clouds.
Tip: Create a separate layer for each point cloud. Placing markers on their respective layers makes it easier to identify which markers belong to which point cloud prior to registration.
The markers on the left serve as reference markers, while those on the right are from the point cloud to be aligned. The transformation is computed to align the right-side markers with the reference markers. This transformation is then applied to the selected point cloud. After placing the markers, the next step is to match each corresponding marker across the point clouds.
The markers in both point clouds should correspond and occupy identical positions within their respective clouds.
- Reference point cloud. This point cloud is the reference to merge with the imported point cloud.
- Imported point cloud. This is the imported point cloud that will be merged with the reference point cloud.
- The final result after the registration, both point clouds merged.
