IMPORT dense point cloud

[MINE]

Hello everyone,

I have a project, where I need to export the dense point cloud, alter it and re-import it into PS, but it doesn't seem to work.

I have tried the following workflow:
1) Simply export the point cloud (File -> Export points) in obj or ply format
2) Deleting the point cloud in the project (selecting it and delete)
3) tried to import the point cloud (Tools -> Import -> Import mesh) unchanged

The problem is that if I try to see the dense point cloud it shows nothing, and says there are 0 points. If I try to show the mesh it shows nothing, but says there are 0 faces and 2.519.351 vertices.

How can I make it work so I can export the dense point cloud and import it back into PS??

Thanks in advance 

[Alexey Pasumansky]

Hello MINE,

Dense cloud import currently is not supported.

Importing point cloud file using mesh option will not produce any good results, because PhotoScan will try to use points as mesh vertices, but there are not any faces.

[gatsri]

It would be verry helpful to import dense cloud. are ther any plans to implement this feature?
Thanks

[Patribus]

+1


I do not understand one thing. When asking about editing point clouds, I get the answer, export it, edit it in some other programs (e.g. MeshLab) and re-import it into PhotoScan. BUT if Photoscan does not support this, how is this meant?

[photogrammetrix]

Hi  alll,

you are right when you say  that importing a point cloud would be  a good feature.

When looking at the python api docu for ps it becomes clear that withtin ps the point cloud is NOT just a simple collection of 3D points with RGB colors and point normals. The point cloud class is a bit more because additionally it  holds the projection information for the points, or in other words. where the 3D points can be found in the 2dimensional  image space of the corrosponding camera.

So when you simply export the point cloud points as x,y,z,nx,ny,nz,r,g,b you will loose this connection. Therefore reimporting a pointcloud that was exported without storing the "connection-information" is not a trivial task.

Alexey, please can you give a comment regarding my interpretatiion, may be I am wrong with this.


Chreers

[Patribus]

Hello,

Ok, I was not aware of this. But it makes surely sense.

Nevertheless, I could imagine a quite 'simple' solution for integrating Point Cloud Importing in PS.

Assuming that the point cloud you are working on externally was generated with PS. In the act of exporting it, PS could generated an additional file containing all the PS-specific information about this point cloud. I assume that the main work to be done in the point cloud externally is 'cleaning', this is deleting points. Now, if I decide to re-import this point cloud in PS, I'll need to indicate the additional file that was created when exporting the point cloud in first place. Since the points position are something like an unique ID, both data files are compared and the PS-specific information extracted and joined to the points remaining after editing.

Surely this procedure would only be available for Point clouds generated by PS, but having such a possibility would be a major improvement.

What do you think? (@PS-Team)

Cheers

[photogrammetrix]

Hi all,

yes I think "point cloud cleaning" is the main thing people have in mind, when exporting the point clouds.

My suggestion is:
Why not implement a couple of algorithm directly within Photoscan?

For example:
1. A conditional point cloud filter, so that we can filter it according to specific attribute constraints, e.g. normal in z-direction not greater than a specific value etc.

2. Statistical outlier filter

For more ideas on possible filtering you may like to look here:

http://docs.pointclouds.org/trunk/group__filters.html

That would save the export/import steps and can maintain the integrity of the pointcloud within Photoscan.

Cheers

[Patribus]

Why not implement a couple of algorithm directly within Photoscan?

Yes, sure, that would be the best thing and you'll find enough suggestions for point cleaning/editing tools for PS.

My suggestion above remains, cause there will be always some user with some exotic editing of point clouds external to PS, so that a re-import should be possible.

Cheers