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

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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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22 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.

     

  • Tha nhcp

    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

  • Avatar
    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 point cloud is to incorporate the geometry from something like a LiDAR point cloud and the texture from images to accompany. If you don't have images then Pix4Dmapper is likely not the appropriate application to use. 

  • Robert Goldsmith

    hiya, how do you setup a new project without any images?

    Thanks

  • Avatar
    Beata (Pix4D)

    Hi Robert,

    Could you explain to me the purpose of such a project? 

    Why would you like to set up a project without any imagery? 

    Thank you in advance.

    Regards

  • Robert Goldsmith

    Hiya

    I was just wondering if we could take point cloud information from a lidar device then create a 3d model based on the cloud.

     

    Thanks

    Rob

  • PINUCCIO D'AQUILA

    Hi ... is it possible to use pix4d images to generate a mesh texture for point clouds imported from third party software?

    Thanks Pino

  • Marco Paccagnella

    Hello! Pix4Dmapper cannot generate a 3D textured mesh based on an external point cloud.

  • PINUCCIO D'AQUILA

    Hi, his response contrasts with Holden's (December 10, 2019) - "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 ... "
    Can you clarify if it is possible to apply a texture from photographic images to third-party point clouds?

    Thanks

  • Holden (Pix4D)

    Hi Pinuccio. My comment was more directed towards the orthomosaic generation rather than mesh generation. Apologies for the confusion. 

  • Jaylene Naylor

    Hi! 

    I am having a similar issue as those above. I have a point cloud from Agisoft and wish to import it. I only have two images associated with the area (two aerial photos from 1995). Am I at a dead end here or can I import a raw point cloud without the photos? Thanks!

    Edited by Jaylene Naylor
  • Michael Taylor

    Jaylene Naylor PINUCCIO D'AQUILA Marco Paccagnella Holden (Pix4D)

    Reading between the lines here and my personal experiences attempting what you were attempting to do was not possible.

    In my Dec 10th 2019 post, I too was using Agisoft (and CloudCompare) in an attempt to import a significantly edited point cloud that was originally created via LiDAR and a surveying software (Leica?).  If you are a user of Agisoft, you may know that there are features therein not available in Pix4D because Pix is meant for generating the RayCloud, mesh, orotho and dtm, etc and therefore it is very limited on cloud manipulation in comparison to other software.

    In my post, I was attempting to import a cloud (XYZ) and create an ortho and others items that Pix4D is capable of creating.  I believed that Pix was capable of creating those products using any point cloud via the import feature and then processing with Pix.  After reading many articles here, I believe that Pix relies entirely upon the RayCloud which relies upon the raw images, and without those raw images, the remainder of the products cannot be produced (i.e. ortho, dtm, mesh).

    The RayCloud seems to be a proprietary, or specifically created cloud and not a "general" cloud as produced by Agisoft or another software, unless the RayCloud is exported in a general cloud format (e.g. XYZ, LAS)

    What I took away from Holden and others is that if you want to import a 3rd party cloud, you must also be able to import the images used to create that cloud. If that is not the case, I would appreciate a detailed response from anyone at Pix4D so that this confusion may be cleared.

    Holden and others have asked why or for what purpose would this serve - to import only a 3rd party cloud without images?

    My needs, and I assume others' needs would be:

    - Where a 3rd party cloud (only a cloud or with very few images) is provided to the Pix4D user and there is a desire to create products found within Pix4D, such as a 3D model.

    I believe that this option is not possible due to the requirements of any photogrammetry software - jump in Holden or Christina if this is incorrect.

    What I would like to know beyond this specific question is - can a Pix4D RayCloud that has been exported as a "general" cloud and then edited in CloudCompare or Agisoft be imported back into Pix4D with the original images and processed in a new project WITHOUT Pix4D altering the imported cloud?  The images would be those used to create the original RayCloud prior to being exported and altered.

    In other words, if I export and edit a cloud from Pix4D and import back into Pix4D and include the images, will Pix4D ignore the imported cloud and recreate a RayCloud or will it use the imported cloud and images to create the mesh, dsm and 3D model?

    I apologize for being verbose and hopefully I have made myself clear.

    Regards,

    Michael.

  • Avatar
    Beata (Pix4D)

    Hi Michael Taylor,

    Indeed, Pix4Dmapper does not have tools like Gradual Selection in Agisoft. But, it is because the software is focused on direct good quality point cloud generation rather than results correction. In Pix4Dmapper to obtain a good quality point cloud, you adjust settings of Step 1 and Step 2. However, you indeed have to master the options and parameters Pix4Dmapper offers to get the best possible result right away. Yet, with our articles, videos and training offering, a person can do it relatively fast. Of course, if somebody wants to work hard on the point cloud, neither Agisoft nor Pix4Dmapper is the right tool.

    The incorrect workflow is to try to generate orthomosaic based on point cloud-only. It won't matter if this point cloud comes from Pix4Dmapper, Agisoft or Lidar. Pix4Dmapper has to have images and results of Step 1 and Step 2 processed to include a new point cloud into Step 3 results generation (DSM, DTM, ortho etc.). Let me know if the process is clear to you now.

    The rayCloud is not a point cloud. It's a visualisation tool that links 2D data (images) to the 3D model. If you are interested, you can read more about it here: https://www.pix4d.com/blog/raycloud-power-understanding-photogrammetry

    To summarize, you could simplify your workflow and not export Pix4Dmapper point cloud to improve it in third-party software and import it back again. Instead, you should adjust the settings and use our tools to generate a very good quality point cloud that does not need almost any improvement.

    However, if you possess a more detailed point cloud (e.g. Lidar) that you would like to include to the processing, please don't hesitate and follow our workflow described in the above article.

    If you have any other questions, let us know. We will be happy to help!

    Have a great day

    Edited by Beata (Pix4D)
  • Christian Dooley

    I've been trying to import external point clouds, and can't seem to get them to line up with the densified point cloud. The point clouds that I'm importing are the same clouds from which I derive my GCPs, so they should reasonably line up with the densified cloud immediately. Instead, they're imported a couple hundred feet away from where they should be. Here's the latest example, but I've tried with other datasets in the past as well.

    Any idea what I'm doing wrong?

    Edited by Christian Dooley
  • Yuka (Pix4D)

    Would you please let us know which version of Pix4Dmapper you are using and more information about the coordinate system?  The external point cloud would need to be in the SAME coordinate system as the output coordinate system. You might want to try Pix4Dsurvey that expands possibilities, enabling the combination of photogrammetry and third party point clouds such as terrestrial laser scanners.

  • Christian Dooley

    Hi Yuka, thanks for the response.

    I am currently working in Pix4Dmapper version 4.6.3. The external point cloud that I am trying to add to my dataset is from a Leica LiDAR scanner. I originally processed my photos with Pix4Dmapper as being an arbitrary coordinate system with ground control points. Those ground control points, which are shown in the above screenshot, are points taken directly from that same LiDAR scan data. I have been bringing the external point cloud into the project as an LAS file, and repeated the process several times to make sure the coordinate system isn't being changed at some point during the process, but I can't find any point where that could be happening. Ideally, since the LiDAR data is the ground control, it should line up when imported into the Pix4D project, but clearly something went wrong. 

  • Yuka (Pix4D)

    Hello Christian,

    Thank you for the explanation. Would you please try it with the other software such as CloudCompare to see if the same issue would occur? 

    Warm regards,

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