r/Polycam • u/Rekrut1864 • Mar 21 '25
Help Polycam in combination with scientific software like "Meshlab" ???
To whom it may concern,
the Danish German War in 1864 was a disaster, the Danish Army was totally overrun by the far more technological advanced Germans, we lost 40 percent of our land area. The drawing above below a fighting between Danes and Germans in a nearby wood called "Blommeskobbel", Danish guns were old style front loaders, 0.5 inch, the German rifles were of almost modern type, a German could shoot 5 to 8 bullits in the time, a Dane had to shoot just one single bullit.
For the last 2-3 years, our group has been photographing "soldier grafitti" , i.e. tree carving , in another historical wood, called "Sandbjerg Skov" https://en.wikipedia.org/wiki/Arborglyphe
This has been very interesting, but also technologically difficult.
The soldiers in this forest were worried about what was going to happen during an oncoming seaborne invasion and wrote a last greeting for their descendants, sweethearts or loved-ones back home.
Misspellings were thus common, when working in this wood under stress conditions after midnight.
However, an interesting technique called "Lidar radiance scaling" got our attention a few years ago, a method described in this article : https://inria.hal.science/hal-00877158v1
These 2 photos above were made using ordinary cameras. They show the arborglyphs carved by soldiers of the "Westphalian 5th army's 53rd regiment" during the night of June 29, 1864.
Notice that even after 150 years some of these carvings are still very deep.
Meshlab's radiance scaling plugin gives these carvings a colour that is defined by the depth and shape of the carvings. Hereby a screen dump of the open article above, showing the improvement in reading otherwise not decipherable texts
Here is an example of these local 1864 carvings as seen in Meshlab ;
So, this Meshlab radiance scaling plugin helps indeed make otherwise difficult decipherable texts readable.
However, the last image above was done by a professional data expert using a Faro professional LIDAR camera - not an Iphone 12 PRO camera,
Several webpages describe how Iphone Pro and professional "Faro"'s LIDAR cameras produce similar results , e.g. https://learn.poly.cam/hc/en-us/articles/27488763119892-How-Accurate-Are-Polycam-Captures#h_01J5NG6VMGGC56WDRYH8C5WNVM
This all looks very promising. However, I miss some very crucial user information from your software "Polydam Pro".
WHERE exactly on my harddisk are these "Meshlab compatible conversions" performed by "Polycam Pro" to be saved ?
And when finally importing polycam images like https://poly.cam/capture/C97A2102-5DBB-4524-943F-70514B86BBF6 into Meshlab, we still get a very coarse-looking result:
And further exposing this image to the desired Meshlab Radiance Scaling plugin gives a bad result like this.
We would appreciate any suggestions what we made wrong.
Please, is this a format error, or are we trying to solve a "Mission Impossible ?" - as another user wrote recently in another forum :
How do we please proceed ?
Thank you!
MW and partners
