Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - Dieter

Pages: 1 [2] 3 4 ... 8
General / Re: Import Laserscan data -registration lost
« on: March 22, 2021, 07:03:57 PM »
Take a look at my coordinates from the ruler, i don't understand this.

Why do you changed my coordinate System?

General / Re: Import Laserscan data -registration lost
« on: March 22, 2021, 05:28:38 PM »
Paulo wrote:

"I was able to load your laser scan tif into chunk 1 and set the EO using quick layout script. Note that estimated yaw is a little different from reference because of grid convergence.Now projection of  Point 1 in Laser Scan  falls close to target but not at center."

Please move reference point 1 in the scan to the mark and watch the deviation, I have 27 pixels. This is too much.
You can also set a new point on the target mark in the scan, and then compare the coordinates with those of the target mark from the photos. The deviation is approx. 55 cm in the high value, 42 cm in the legal value and 20 cm in height.
In contrast to the photos, the scan is shifted, although this should fit.

What i've done:
-read the Original Project
-input laserscan
-run your script
-move Marker 1 to Target in the scan, this should fit with the Foto orientation!
-watch the derivation-> 27 Pixel

-read the Original Project
-input laserscan
-run your script
-Set a new Marker Point 1 to the target in the Laserscan
-watch the derivation between Marker 1 (Fotos) and Point 1 (scan)
-you will see the difference

General / Re: Georefrence Setting and GCP
« on: March 22, 2021, 10:46:03 AM »
I have the same problems.

When transforming the data under Georeference control points, you must first enter a coordinate system that is valid for your region, regardless of whether you are working with local coordinates.

For me in Germany the UTM 32 N.

Then you can also enter local coordinates for the control points, the main thing is that the WGS84 coordinate system is converted into a projected coordinate system.


General / Re: Import Laserscan data -registration lost
« on: March 22, 2021, 10:02:42 AM »
Thank you for the quick reply, here you can find the data:

-Metashape Project
-Fotos as JPG-File
-Scan as Tif-File
-coordinates Fotos as TXT-File

The coordinates of the Scanner are 9014.849 8336.246 491.459 and they are correct calculated.

The Project is in status after Point 4 of my list. The coordinates has been converted to my own coordinate-System ETRS89 / UTM zone 32N Meistersehl and match to the scanner-coordinate-System.

Please import the tif-file of the Scanner and run your script, then push the update Button, all coordinates are wrong now.

Point 1 you can find in the fotos and in the scan-file.


General / Re: Import Laserscan data -registration lost
« on: March 21, 2021, 12:42:34 PM »
Something must go wrong with the coordinate systems, I can't get the laser scans and cameras to cover.

My project consists of 5000 drone photos with PPK coordinates. In addition, 3000 photos were taken by hand, without coordinates. I imported the drone photos and the others, had them aligned and converted to UTM32. Then I created my own coordinate system, which only contains the last 4 coordinates of the UTM coordinates. Then 25 laser scans with the same coordinates (only the last 4 digits) were imported in the same coordinate system and the coordinates were set as calculated coordinates with your script.

Everything works perfectly, control points, which were determined in the photos (not reference Points), appear in the right place in the laser scans with gray symbols. But if I now determine a point in the laser scan, the coordinates deviate by 25 cm from the target coordinates. There are some differences in the coordinate systems that I cannot explain to myself.

If I unmark all photos as a reference and then press update, the coordinates are the same, when i Import a scan, run your script, den press update, the coordinates shift by the same amount and nothing matches any longer.

Even a convert in "Local Coordinate System" make no change.

I did a test with a smaller project.
1) Import photos with PPK coordinates
2) Calculation with the coordinates as control points
3) The result is correct, the error is 1 cm.
4) Conversion of the GPS coordinates to utm32
5) Reading in the scans with coordinates UTM32
6) Start your script
7) Everything seems ok, all coordinates are correct, points that were determined in the photos correspond graphically to the laser scans on the screen.
8) When I determine a point coordinate from the laser scans, the coordinates are NOT correct. When I click on update, all coordinates shift and nothing is right anymore.

How can I solve the problem?

General / Re: How to find best texture size setting ?
« on: March 15, 2021, 01:32:03 PM »
This is a simple calculation, here is an example:

If you have a texture size of 4096 * 4096 pixels and want a texture accuracy of 1 pixel = 1mm, you cover 4096 * 4096 mm2, that is divided by 1000000 (mm2 in m2) = 16.7 m2.

You get the information about the surface from Metashape, you can choose the size and number of textures yourself.


General / Re: Import Laserscan data -registration lost
« on: February 01, 2021, 12:05:32 PM »
Hello Dieter,

Yes, it would be helpful to share the project (in the state prior to the merging operation) and brief description that we should follow to reproduce the problem on our side.

Hi Alexey,

were the problems understandable?

Since the latest versions, I am no longer satisfied with the dense point cloud. The basic setting of the images to be evaluated in parallel is too low.

You can change this by making an entry under the advanced settings: "BuildDenseCloud / max_neighbors = 1000"

I work with 1000 to get good results. Since you only have 864 images, you can play around with the settings here. A "-1" always means evaluating all images for the dense point cloud in parallel. Then you have the best point cloud, but the evaluation also takes the longest.

I would also set the filtering to aggressive.

General / Re: Import Laserscan data -registration lost
« on: January 25, 2021, 03:40:51 PM »
There are two chunks: scan and photo.

In the first chunk, the scans were read in and referenced with your script. The scans were then set as a reference with an accuracy of 1 mm. Then control points for the photo chunk were determined in the scans and output as a file.

In the second step, the photos were read in and aligned. Then the photos were referenced and balanced using the control points that were determined in the scans. The control points were set as reference with an accuracy of 5mm.

In the third step, I wanted to merge the two chunks, as they are created differently (photo and scan), but are based on the same coordinates. After that I would have the dense point cloud, mesh, etc. generated.

But that doesn't work that way. After merging the chunks, the references no longer fit and I get differences of up to a few meters.

Here is the link:

General / Re: Import Laserscan data -registration lost
« on: January 25, 2021, 10:42:58 AM »
I'm afraid that after merging the scans with the photos, the reference will be destroyed. It looks as if the scan chunk is too large by an incorrect scaling factor, and as a result the coordinates of the chunks no longer match.

Should I make my model available or can you understand this with your own data?

General / Re: Import Laserscan data -registration lost
« on: January 25, 2021, 10:00:14 AM »
Okay, I spoke too soon.....

When combining a laser scan project chunk with a photo project chunk the error message "incompatible keypoints" appears, but the chunks are merged.

Is this a problem?

General / Re: generate dense cloud from laser scan
« on: January 25, 2021, 09:52:11 AM »
Try to save the project before generating the dense point cloud. Without this step, I always had a crash.

General / Re: Import Laserscan data -registration lost
« on: January 24, 2021, 09:50:37 PM »
I've done a few tests now, what can I say, it's going perfectly for me so far.

Many thanks for the very quick implementation of the function.


General / Re: Import Laserscan data -registration lost
« on: January 23, 2021, 02:15:06 PM »
Dear Metashape team, I am happy to provide my data.

I uploaded 5 point clouds, once as an aligned Metashape project and once as original E57 files.

As you can see, the point clouds are not scanned in color. In this case it would be nice if the intensity images were not only displayed in the image processing window, but also as an image preview. At the moment, the image shown as a preview can hardly be seen.

Scan 5 could not be aligned over the 360 ​​° images because it has too little overlap. However, it has the correct coordinates and the correct rotation from our scan calculation program.

It would be very desirable if Scan 5 could now be included in the mesh processing due to its known orientation.

It would be a great advantage for us if the scans were also included in further processing without alignment, as these are normally already available with their orientation and are condensed with photogrammetry or a texture is assigned to them.

Here is the link to download:

General / Re: Import Laserscan data -registration lost
« on: January 21, 2021, 08:41:48 PM »
Same problem here.

I first have to allign the 360°-Pictures, then it works.

But should it work without allignment? The coordinates and orientations are known...

Pages: 1 [2] 3 4 ... 8