Boat Survey: Kifanlo several technics comparison

Kifanlo part1

Presentation

Built in 1955 in Les Sables d’Olonne, the KIFANLO was classified as a historical monument in 1984. She is one of the 16 identical hull trawlers launched by the Batifort shipyard between 1945 and 1957. The Kifanlo is a tuna trawler made of wood with mixed propulsion. She is 16.37 metres long, with a tonnage of 27.51 tons, and is equipped with a 120 hp Poyaud engine. (more at https://oceam.org/presentation-du-kifanlo)

Le Kifanlo fête ses 60 ans | Le Journal des Sables

https://actu.fr/pays-de-la-loire/les-sables-d-olonne_85194/le-kifanlo-fete-ses-60-ans_9405650.html

The boat is being restored, and before any action, we conducted a photogrammetric survey.

Methodology

Several methods have been used in order to compare metrological results: classic from camera shots, using IPad pro and Lidar and 360 camera.

O:\--KIFANLO--\IMG_1458.JPG

With DSLR camera

dslr camera give with no surprise excellent results.

With 310 cameras the model is covered.

Aligned with sparse cloud

Dense cloud with 61, 166,938 points !!!

Reconstructed model, meshing

The model is cleaned, the aim here was to keep only the hull to study the deformations.

After removing the ground and stands

See the simplified model exported in sketchfab

Test with 360° camera

The test with the Theta Z1 360° camera gave also pretty good results. For this test, a film was short circling around the camera. This images were extracted from the film. For this test, 400 images were used.

https://youtu.be/PLngtfCL7oM

The sparse cloud is wider and shows more unwanted sky and cloud artefacts

Dense cloud

But despite this, the hull is complete and with a very accurate precision.

Cleaning

Meshing

Texturing

Test with Ipad

Metascan is one of the available Lidar scanner on IPAD pro.

Surprisingly the scan at this very large scale is possible and it gives pretty good results. The advantages are that the model is at scale. It is then possible to have an accurate model in terms of size and proportions.

The USDZ file from Metascan is there upload to Sketchfab.

An issue is visible here and the junction of the starting position and ending position

With Sketchfab we see that scale and floor position are correct

Sketchfab

Another test with 3dscanner App gives similar results

There again, the closing the model is problematic.

Update

Artificial Intelligence now allows to calculate photogrammetry.

Here’s the result…not bad. If the texture is poorly define, the rudder and the propeller are more accurate.

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