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Topics - dcobra

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General / V1.7.0 - Increased RMS reprojection error
« on: January 05, 2021, 09:26:33 PM »
I've noticed an increase in RMS reprojection error in V1.7.0 compared to V1.6.5.  I have attached screen shots of project info from a model processed with the same parameters in both versions.  In V1.7.0 RMS reprojection error is 0.424 px and in V1.6.5 it is 0.331 px.  I also notice that there is a notable decrease in the number of tie points in V1.7.0.  I'm assuming that the difference in RMS is attributed to how the tie points are being selected and filtered.  Also interesting is the increase in tie point multiplicity and increase in max reprojection error in V1.7.0.

Is this expected behavior and why is it happening?  Does this have any effect on model accuracy?  Any advice would be greatly appreciated.

General / Export Camera Calibration with Additional Corrections
« on: November 14, 2020, 03:01:31 AM »
Is there anyway to export the camera calibration and include the additional corrections?  I would like to use a calibration from one project on another.

Or is there a way to include "fit additional corrections" when optimizing a project when the camera calibration is fixed?  Fit additional corrections is currently greyed out when trying this.


General / V 1.6 marker accuracy weighting
« on: March 11, 2020, 02:55:49 AM »
I have noticed that there has been a change in how Metashape weights marker accuracy (measurement accuracy) from V 1.5 to V 1.6.  Marker accuracy seems to have a much stronger weighting in V 1.6.  Lower values (below 0.001m) tend to force the point cloud to conform to the control points, whereas in V 1.5 there was much less of an effect.  The error observed on control points is reduced as the accuracy value is lowered.  Can Agisoft confirm the change and provide some additional info?  Have the other weightings been changed?

Attached are two screen shots of the same project optimized in V 1.5 and V 1.6 with marker accuracy set to 0.0001m.  Note the error on control points is much lower in V 1.6.


General / V 1.6.0 - Dense cloud generation time longer, increased noise
« on: January 14, 2020, 06:58:25 AM »
I have processed the same project in 1.5 and 1.6 and the dense cloud in 1.6 takes longer to generate and the result is much noisier.  Have tried the max neighbors tweak = -1 with no improvement.  Anyone else experiencing similar issues?

General / Camera Calibration and Distortion Plot
« on: March 07, 2019, 11:27:17 PM »

I've been experimenting with camera calibration parameters and have processed a model with two different configurations.  The configurations are as follows:
1 - F, Cx, Cy, B1, B2, K1, K2, K3, K4, P1, P2
2 - F, Cx, Cy, B1, B2, K1, K2, K3, K4, P1, P2, P3, P4

These two configurations give quite different distortion plot results and I am trying to understand the meaning of them (see image attached).  The first distortion plot seems quite realistic, increasing distortion with increasing radius.  The second distortion plots looks odd, but gives better RMSE on check points, and there is lower distortion in the decentering plot.  Is the second plot realistic?  Or is it a case of over parameterization? Any advice you have is appreciated.

General / Lines in Dense Cloud
« on: January 16, 2019, 05:05:08 AM »
I have noticed some odd lines in some recent dense point clouds.  They are quite visible when viewing the model from the backside.  The lines are raised slightly beyond the backside of the actual surface of the model.  See screenshots attached as an example.  Dense cloud was processed using Metashape 1.5.0.  Any guidance as to what is causing this and how to remedy would be appreciated.

General / Optimize cameras after changing coordinate system?
« on: January 12, 2018, 03:24:08 PM »
I processed a dense point cloud and mesh that have control points but no camera georeferencing.  The coordinate system I used was NAD83 EPSG4954, and now I found out that the control points were actually in NAD83 EPSG2953.  I'm wondering if I can just change the coordinate system in the reference pane and the models will adjust, or if I need to re-optimze the cameras and reprocess the models afterward the change. 

Thanks for any help.

General / Resize region automatically
« on: December 13, 2017, 07:12:07 PM »
I have almost 250 chunks that I created with the split into chunks script and have generated dense point clouds in each.  I would like to resize the bounding box region in each chunk to the size of the dense point cloud before I mesh them.  Is there a script that can do this automatically? 

General / Mesh generation stuck, no disk swap occuring
« on: November 19, 2017, 10:46:55 PM »

I'm building a fairly large model that has been split into chunks and am having issues generating meshes.  Project is ~5000 20 Mpix images.  Hardware is a 2008 Mac Pro 2.8 octo, 42 GB Ram.  Using photoscan 1.3.4 professional version.  Project file is saved on an internal drive dedicated for storage, not the system drive.

I aligned all of the images in one chunk and after adding CPs split the project into many chunks using the split code provided by Agisoft. I want a very detailed models and prefer smaller models for use in a visualization tool once the models are complete so I split into ~260 chunks.  The dense point cloud processed without any problem.   I am now trying to mesh the dense point clouds and am having varying degrees of success.  Meshing will start off well and then after processing 2 - 6 chunks it gets stuck and I can leave it over the weekend without any progress.  Progress bar just sits on a percentage completed and elapsed time increases.  CPU has essentially no load.  There does not appear to be any swap occurring and total RAM usage tends to only reach ~20 GB so it doesn't seem like a RAM issue, which is what I have read is the common problem with mesh generation getting stuck.  The dense point clouds are 10-20 million points, and I would estimate that there are <50 photos in each bounding box.  The process doesn't necessarily fail on the largest point clouds.  The only remedy is to force the application to close and restart the machine.  If I force close but don't restart the problem happens again right away on the first mesh.  After I restart I can process a few more meshes.  I have deleted most of the cameras that are not within the bounding box in each chunk as a potential fix, although I did leave some on either end of each chunk.  This hasn't made any difference. 

Any ideas as to why this is happening would be greatly appreciated.  Could chunks that are too small be causing the problem? 

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