Topics

1

Face and Body Scanning / Two-fold alignment in point cloud

« on: July 16, 2018, 05:49:10 PM »

Hi all.

First of all thank you in advance for your reading.
I'm in trouble trying to making 3D model of a set of rare abyssal fishes for the Spanish Institute of Oceanography. I made 151 photographies of the subject very accurately, using tripod and a f-value of f/18 on a 100mm macro lens, rotating around the subject with very constant lighting. When depth field was not enough and not all the subject was on focus I pointed to a certain area of the fish, shot it, moved slightly, pointed to the area that was out of focus before and shot again.
I successfully employed this technique with other models and everything went well.
What I'm obtaining now is a strange two-fold points cloud, with most of point correctly aligned and a large part of them misaligned over a symmetric and specular fold of the original cloud.
Please see the attached figure to understand what I mean.
Photo alignment with High quality, generic pre-selection and adaptive camera model fitting enabled.
Any idea of what is occurring?
Any idea of how to detect the images responsible for the misaligned part of the cloud?
Any idea of how to force photo alignment to be coherent with the other part of the cloud?

Thank you in advance.
Best regards
Simone

2

General / Poor mesh with good dense cloud

« on: December 19, 2017, 06:29:11 PM »

Dear all.
I'm making a 3D model of a stuffed shark and I'm struggling to obtain a complete and correct mesh. The dense cloud is generally very good and reproduces very well the animal, but in some areas the derived mesh is holed. In particular the tail is great in the dense cloud but it is later not correctly reconstructed in the mesh. What I noticed is that the dense cloud class shows pixels with not exactly the same colors (they are mainly gray and some of them are black) and I noticed that the black ones are not used for the mesh and let the holes. I did not use dense cloud classification.
What are those black pixels in the dense cloud?
Why the mesh does not use them?
Thank you in advance.
Best regards
Simone

3

General / Zenital plus oblique photos for real estate photogrammetry

« on: July 15, 2017, 10:44:43 AM »

Dear all

First of all, a big hello to everybody and thank you for having created such a cool community of such a powerful software.
I'm really happy with Photoscan, using it as the main tool for photogrammetry of real estate.

Unfortunately there is a magnific villa here in Costa del Sol, in Andalusia, which is causing me several headhaces.
It is a detached villa with a quite large and very articulated roof and a wide garden with a pool.
All concerning the zenital flight worked like a charm.
A lot of details and perfect geometric coherence in the mesh. No problem at all.

One "funny" feature of that house is that the roof oversteps the perimeter of the internal house and create a sort of canopy all around the structure. While it is really confortable to take a cup of tea shielded from Spanish hot sun, it is a nightmare for a correct 3D reconstruction of the whole house and its vertical walls. These walls are indeed "hidden" by the canopy and are only partially seen by the drone flying over the house.

In order to cope with this limitation I included in the flight a new set of oblique photos all around the house, taken manually while I was travelling along the perimeter of the villa. In the following images you can see the zenital set of images and the belt of oblique perimetral ones.





You can also see how only a portion of those images are displayed as blue squares, while few of them, especially the ones on the opposite side of the house, are depicted as circles. As far as I understand it means that these photos have not been correctly georeferenced/matched/used to extract point clouds.

Since the oblique images include a piece of sky I masked them to take into account only the portion from the border of the roof downwards.



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