PTS Export Stripping out Normal values

[edward_triplett]

Hi, 

I imported a .PTS photogrammetry point cloud, made my edits in ReCap 1.3.2.500 and exported pieces of the cloud in .PTS format and everything gets exported EXCEPT the Normal information. I can see that the normals were imported correctly when I turn on Normal color mode in Recap, but the exports are stripping this information from the exported pieces. How do I ensure that the exported clouds contain all my information : XYZ, RGB, N1 N2 N3 ?

Thanks

[ryan.frenz]

The PTS format doesn't have an official standard, but in LiDAR software it's usually XYZIRGB (sometimes without the intensity).  Yours is the first file with extension '.pts' I've seen that contains normals.  What software did it come from?

ReCap contains a configurable import tool, but not export - so you're limited to the standard PTS output.  Having the same configurability on export is an interesting thought.

What software package are you targeting?  Most of them should be able to recompute the normals on import.

Ryan

[edward_triplett]

The data was created in VisualSFM and I found ReCap perfect for cleaning the somewhat fuzzy results before meshing in MeshLab or CloudCompare.

I exported to .PTS from CloudCompare initially in order to import it into ReCap. CloudCompare's import function asks the "meaning" of each column in the imported cloud. The way I knew ReCap was not exporting the last three columns is because CloudCompare was only asking about the XYZRGB after the same cloud was cleaned and exported from ReCap. 

As for recomputing the normals, this has been a poor solution for me in the past. The Meshlab calculations never give as accurate a calculation as the original normals. Is there any way to merge the normals from teh original (before ReCap) onto the corresponding points of the timmed cloud?

Thanks.

[ryan.frenz · Accepted solution]

You can configure ReCap to read & use your input normals (see the Text Options pane during import).  But at the moment there is no way to export the normals back out.  ReCap's export only does standard PTS (RGBIXYZ) - it is not configurable like the import.

I assume having the normals as part of the export helps with creating a mesh.  This is an interesting workflow - I'll make sure this gets on the list for consideration for a future release.

Ryan

[edward_triplett]

Thanks for looking into it. I will have to find a way to add the normal fields with a script. I will keep an eye out for this change to ReCap. I really think it has a lot of utility. I see Recap's indexing as the solution to large but messy photogrammetric point clouds created from outdoor photographs because masking the sky out of these photos in pre-process is too time-consuming. ReCap can trim out unwanted blue-sky and white-cloud points much more easily than any non-indexed cloud viewer. The only hang-up I have found has been the limited number and type of export options. ASCII export options like .txt .asc or .xyz that could keep all of the original cloud's info as you explained would be a great addition.
Thanks for answering.

[jyoung]

Re calculating the normals especially on large data sets takes a long time. Is their any format that can export normals from recap?

[vkasireddy]

Is it XYZIRGB or RGBIXYZ? After exporting from Recap, I imported the file into CloudCompare. It seems to be showing XYZIRGB. Could you clarify?

Thanks.

[humberb]

Oops, sorry for the confusion! You're correct that the latest version of ReCap 360 will export PTS files in the order XYZIRGB.

[costermonger]

It has been four years. Why aren't normals exportable in a configurable text the same way they are imported?

[jay.stocker]

I agree!! This is kind of important. It's a real limitation.

How can you have a viable workflow when there is no way to transfer important information between programs??

Recap has the same problem when importing: it is limited to recognising only ONE scalar field value per point, whereas CloudCompare allows you to have as many scalar field values as you want! How can I include Recap in my workflow if it strips out most of the information?

[rodbrew2]

Yes this is so frustrating.  It seems that everytime Faro upgrades Scene it breaks CloudCompares ability to import Faro Scene files.  Being able to use the scanner generated normals is so much more accurate and faster for building meshes.  Faro Scene only outputs normals to .pod files and I think one other format.  Was hoping Recap could output normals but apparently not.  I'm not sure how normals work under the hood coming from a scanner but it would be nice to get a format "normalized" for lack of a better word.

[andyp7]

It's been 6 years. Still no way to export the normals that my LIDAR scanning is providing? Instead you're stripping out useful data.

Why can't we retain this normal data?

[Greg.Painter]

In 4 days time it'll be 10 years since this issue was raised and ReCap still removes normal information on export.