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How to import a Point Cloud delivered by an External Source into PIX4Dmapper for processing

It is possible in PIX4Dmapper to import a point cloud generated by an external source like LiDAR. PIX4Dmapper will use this point cloud in order to generate the DSM, orthomosaic, and other outputs after processing step 3. DSM, Orthomosaic and Index.

The imported point cloud cannot be visualized in the rayCloud and it only has processing purposes. To visualize an external point cloud: How to visualize a Point Cloud in the rayCloud.

  • Before proceeding with the import of the point cloud, you need to create a project and process Step 1. Initial Processing.
  • The external point would need to be in the SAME coordinate system as the output coordinate system.
  • The point cloud generated by PIX4Dmapper and the external point cloud should be aligned. Mark common GCPs in both the model generated by Pix4Dmapper and the external point cloud to align them. If this is not possible, extract points from the Pix4Dmapper model and mark them as GCPs in the external point cloud: How to align projects.
  • If the external point cloud is a DTM, the Orthomosaic may present distortions.
  • All imported points will be treated as a unique group meaning that if the external point cloud is classified (e.g. some points have a terrain or object label), Pix4Dmapper will not take the classification into account. If only points corresponding to the terrain class are imported then the DTM will be generated accordingly.
  • The imported Point Cloud can not be used to generate a 3D textured mesh.

In order to import the external point cloud, follow the steps:

1. Create a project: Step 2. Creating a Project.
2. Click View > Processing.
3. Run only step 1. Initial Processing.
Ensure that step 1. Initial Processing is activated and that step 2. Point Cloud and Mesh and step 3. DSM, Orthomosaic and Index are deactivated.
4. Click Start.
5. Once the Initial Processing is completed, on the Menu bar, click Process > Import Point Cloud for DSM Generation...
6. Navigate to the point cloud file that should be in .xyz, .laz, .las format.

Tip: The .xyz point cloud is not georeferenced. It is recommended to add the .las or .laz point cloud that are georeferenced.

7. (optional) Deactivate step 1. Initial Processing and Step 2. Point Cloud and Mesh and activate step 3. DSM, Orthomosaic and Index. Run only step 3. DSM, Orthomosaic and Index to generate the DSM and orthomosaic based on the external point cloud.
8. Click Start.

  • If the project is already created and processed, follow only steps 5-8.
  • If step 3. DSM, Orthomosaic and Index has already been completed for this project, existing results will be overwritten when running step 3 again. The existing results need to be saved to another directory in order not to be overwritten.
Important: There is a limit in the imported point cloud size that depends on the available RAM. If the point cloud can not be imported, reduce the size of the point cloud and try to import it again.