How to import a Point Cloud delivered by an External Source into Pix4Dmapper

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 can 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. 

 
Warning:
  • The external point would need to be in the SAME coordinate system as the output coordinate system. If no GCPs are used, then the coordinates of the point cloud should be in the corresponding UTM zone.
  • 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 form the Pix4Dmapper model and mark them as GCPs in the external point cloud: How to align projects.
  • When using an external Point Cloud, objects drawn in the rayCloud Editor will not be taken into account to correct artifacts.
  • 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.

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.

 
Note:
  • 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.
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8 comments

  • Resson -

    I'm having trouble with importing a LAS dataset. Each time I import the file into Pix4D, Pix4D states the file is empty, and fails to process the project. I've tried clipping the LiDAR set that I have as well as converting to XYZ. I have also set the Z value coordinate system to arbitrary. I have been unsuccessful in each attempt. What can I try to make this successful?

  • Daniel (Pix4D)

    Hello,

    That error usually happens when the LiDAR point cloud is far away from the project.


    Please check:

    - Both the project and the LiDAR point cloud are given in the same coordinate system
    - The heights of the point cloud are the same as the ones in the rayCloud.

    Thank you very much.

  • Lorcan Scully

    Hello,

    Once I have imported my las file from an exernal source (in this case I would like to use laser scan data from a Leica RTC 360) can I use this point cloud as my DSM for creating an orthomosaic of terrestrial or aerial images collected separately?

    We are trying to create an othomosaic of a building facade.

    Thanks

  • Daniel (Pix4D)

    Hello,

    In order to create an orthofacade, there is another article which will help you a lot: How to create the orthomosaic of a facade

    Regards.

     

  • Thanh Cao

    Hi

    I'm using Pix4Dmapper trial. I have followed the steps as the above article. But I don't see where external point cloud that I have imported (.las format and same coordinate with point cloud in Pix4D). I run only step3 then but the DSM results are not generated from an external point cloud. Could you help me, it is nice if that is a video tutorial? 

    Thanks so much

  • Gaël (Pix4D)

    Hi Thanh,

    My colleague Beata answered your questions on this community thread. 
    Hope it will solve your issue. If not, don't hesitate to continue the conversation on the community.

    Best

  • Michael Taylor

    Hello,

    I am attempting to import an XYZ point cloud as stated in the instructions above.

    In the instructions, it sates that I must start a new project and therefore I must add images to continue and be presented with the Pix4D interface where I may access the rayCloud options.

    I only have access to the point cloud and no images and therefore, I cannot continue into the Pix4D user interface where I can view and manipulate data.

    - Is there a way to import the point cloud directly, similarly to the import option found in Agisoft?

    I have read the following:

    https://support.pix4d.com/hc/en-us/articles/202560759-How-to-visualize-a-Point-Cloud-in-the-rayCloud

    https://support.pix4d.com/hc/en-us/articles/202557309-Step-2-Creating-a-Project#label1

     

    Thank you,

    Michael.

    Edited by Michael Taylor
  • Holden (Pix4D)

    Hi Michael. Pix4D is primarily a photogrammetric processing engine. If you don't have images what is it you are trying to do? The purpose of importing a 3rd party pointcloud is to incorporate the geometry from something like a LiDAR pointcloud and the texture from images to accompany. If you don't have images then Pix4D Mapper is likely not the appropriate application to use. 

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