Imported, external point cloud from Pix4D used to generate 3D triangle mesh

PIX4Dmapper PIX4Dmapper Questions/Troubleshooting
1

I have a point cloud from a different version of my original project that I am attempting to import into my original project. I watched the Radio Tower Reconstruction video, but in the video Mark imported a point cloud but did not use that external point cloud to generate the triangle mesh. So is it possible to regenerate the triangle mesh from my original project using an external point cloud that was imported from a different version of my project?

Basically there are pieces of my original project that are not showing up, and when i lower the matched points from 3 to 2, the items show up, but a lot more unnecessary noise shows up that distorts my project. Now I know you can edit the raycloud and remove noise, but after I do that and regenerate the 3D mesh, buildings will still be warped. On the original version (matched points is set to 3) everything looks fantastic except for the fact that a piece of a building is missing because there was less data for that part.

So my solution was to import the point cloud from the original into the other version (matched points set to 2) to get that piece to appear. Overall the point cloud looks great, but the triangle mesh disregards the imported, external point cloud and when I click the check box for the triangle mesh the part of the building disappears again. Is my solution possible for this type of thing, or should I find a different one? If it is possible to generate the mesh based off of an imported point cloud what is the procedure for this? Thanks in advance!

2

Hi John, 

External Point Clouds can only be used to create outputs such as the Digital Surface Model (DSM) and Orthomosaic that are created in step 3. DSM, Orthomosaic and Index. There is an article that summarizes this topic : https://support.pix4d.com/hc/en-us/articles/202560049

However, if this external Point Cloud was created in a Pix4D project from an earlier version. We would suggest the following workflow: 

  1. Open the project in a new version of Pix4Ddesktop. When opening the project it will ask if a backup should be made, we would click yes.
  2. Merge the two projects to get a better Point Cloud, as described here: https://support.pix4d.com/hc/en-us/articles/202558529 

This should make it possible to use this additional data for the generation of the 3D Mesh. 

Regarding the Minimum Number of Matches, something to try would be to use 2 (so that the area with few matches is reconstructed), but to select “Low (fast)” for the Point Density parameter, which might reduce the amount of noise. 

Cheers