Topics

1

Bug Reports / Colourise Laser Scan bug / odd behaviour

« on: September 11, 2023, 10:31:47 AM »

As part of my ongoing effort to find a solution to the question I posted here: https://www.agisoft.com/forum/index.php?topic=15820.0, I have found an odd and frustrating issue with colourising imported LIDAR (SLAM) point clouds.

When we set the point cloud to 'use as laser scan' and then try and colourise this from our images that we have manually aligned to the scan, Metashape seems to duplicate the LIDAR to make a regular point cloud copy and colours that, moving the point cloud somewhere else as it colours it. This is frustrating as most of our SLAM data has been aligned to a control network using GCP's.

Our only workaround for this is to remember to change all the 'laser scans' back to regular point cloud objects prior to running the colourisation.

Is this a bug or is this the expected behaviour?

2

General / Align images using SLAM data/trajectory and images - V2.0.2

« on: September 07, 2023, 01:33:28 PM »

Is there a way in Metashape V2.0.2 to use the point cloud and trajectory file to automatically align the cameras more accurately?

We are seeking a method to leverage point clouds (SLAM data) to aid in aligning images captured simultaneously from a fixed point on the SLAM device.

Typically, our SLAM files are aligned to control points (GCPs) during processing, ensuring that the SLAM Lidar data serves as the reference.

Currently, we use Metashape for image alignment, but the initial results are not accurate enough to colourise the SLAM point cloud effectively. We import the SLAM point cloud and its trajectory, then manually add markers throughout the image sequence to achieve better alignment with the point cloud.

I had hoped that we could employ the point cloud and trajectory file to automate the camera alignment process, achieving greater accuracy.

A similar workflow exists for TLS (Terrestrial Laser Scanning) scans, which appears to use embedded images to assist in alignment. However, when attempting to align our data, it seems this method does not work effectively with our non-TLS data, likely because we don't have embedded images.

Is there a specific approach or feature in Metashape 2.02 that allows us to harness the point cloud and trajectory file for more precise camera alignment?

3

Bug Reports / Normals not being created from Trajectory

« on: March 14, 2023, 11:47:03 AM »

I have been testing out Metashape 2.0.1 for importing SLAM point clouds and it looks like the create normals from Trajectory is not working anymore.

I noticed that the workflow has also changed. It seems that you now have to import a trajectory file before you import your LIDAR (SLAM) point cloud, which is then supposed to get used for creating the normals on the imported cloud (unless I am missing something).

The following images are screenshots from Metashape 1.8.4 where the trajectory import generates correct normals. The second image is from Metashape 2.0.1 where the normals are showing as incorrect.

4

General / Enable/Disable cameras by distance from each other

« on: December 21, 2022, 02:36:48 PM »

I have some projects that have been created by creating stills from a 360 video. To allow us to get an accurate alignment, I have been using a frame every 2 seconds. This is way too many images for my final requirement so what I was hoping for was a script or an easy way to only have camera's enabled every nth meter from another enabled camera and all the rest to be disabled.

Does anyone know of a way to achieve this?

5

General / Hovermap SLAM normals

« on: November 01, 2022, 05:53:38 PM »

Hi, I have some SLAM data that I have captured using Emesent Hovermap and I am trying to take them into Metashape so that I can colour the data using a set of spherical images I have captured at the same time. The problem I am having is that the SLAM data does not have normals and Metashape calculates them with a LOT of inverted normals. This is a capture of an oil and gas facility so there are a lot of pipes, walls and other multi-shape objects.

I have created a chunk and imported our spherical images and aligned them perfectly, then I take the SLAM data in and want to colour it based on the following tutorial: https://agisoft.freshdesk.com/support/solutions/articles/31000157888-colorization-of-the-external-dense-cloud-lidar-based-on-images

The colourisation process works great, it is just the SLAM data that is proving a real headache to generate correct normals for.

I have tried to up the setting to over 200 on 'Generic' during import but this does not help too much. I noticed that there is an option to use a trajectory file (which I have from the Hovermap scan). When I select this option, it just appears to create the normals from the origin of the scan and not along the trajectory. I have tried to strip the trajectory xyz file so that it only contains the fields mentioned in the importer (time,x,y,z) but again, this does not help. I'm guessing the trajectory file must be a specific file and not just any trajectory file.


Can anyone offer any advice on how to get the point normals created correctly or a script that would flip all inverted (black) normals in Metashape? It is seriously frustrating. I have tried to create normals in Cloudcompare but that is also all out of whack.

6

General / Keep Server jobs on Server quitting

« on: August 11, 2021, 10:18:38 AM »

I there any way for the Metashaoe server to keep the progress and list of jobs it is working on when it quits/closes?

Every time our PC that the server is running on has to restart, or if it crashes, we lose all the progress of the network processing and all jobs have to be re-submitted from the start again.
This has lost days of work sometimes.

All other server/node setups that I have used in the past have a folder where the network jobs are stored and they will just pick up processing from where they left off If there is any hardware faults/crashes etc.