Obtaining cross sectional area and/or width along axis

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Amaya
Posts: 3
Joined: Mon Dec 27, 2021 10:34 am

Obtaining cross sectional area and/or width along axis

Post by Amaya »

Hello CloudCompare community,

I am currently trying to obtain the cross sectional area, surface area, volume and/or the width in certain directions along the length of a 3D mesh
(as in Figure 1 (step 4) of the article of Dickinson et al. 'Registering methodology for imaging and analysis of residual-limb shape after transtibial amputation',researchgate link: https://www.researchgate.net/publicatio ... amputation, and/or figure 5 in the article of Cullen et al. 'The Use of Smartphone Photogrammetry to Digitise Transtibial Sockets: Optimisation of Method and Quantitative Evaluation of Suitability', see below)

I am starting by making multiple slices of the mesh along an axis through the 'cross-section'-> 'export multiple slices' tool. Is there now a way to automatically extract the width or cross sectional area for each slice (and preferably be able to easily export this to make a figure)?
I hope someone can help, thank you in advance.

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daniel
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Location: Grenoble, France
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Re: Obtaining cross sectional area and/or width along axis

Post by daniel »

Ah no sadly... especially since the slices exported by this tool are also meshes (and not polylines). CloudCompare is not very good with meshes...
Daniel, CloudCompare admin
Amaya
Posts: 3
Joined: Mon Dec 27, 2021 10:34 am

Re: Obtaining cross sectional area and/or width along axis

Post by Amaya »

Thank you for your reply. Would it be possible if I were to do it with a point cloud?
Amaya
Posts: 3
Joined: Mon Dec 27, 2021 10:34 am

Re: Obtaining cross sectional area and/or width along axis

Post by Amaya »

Next to this, I was wondering whether it is possible to find the average model (or at least the average distance of multiple models to a golden standard model) of multiple meshes/cloud points, as they seem to have done also in the article of Dickinson et al.
Image.
I could merge multiple clouds and look at the distance of that one to the golden standard, but I don't think that would be correct, as it still has all points of the previous clouds rather than merging to some kind of average model.
If anybody knows how to do this, please let me know, I would be grateful for your help.
DA523
Posts: 166
Joined: Mon May 25, 2020 4:02 pm

Re: Obtaining cross sectional area and/or width along axis

Post by DA523 »

Manually

Edit >> Mesh >> sample Points (1m)
Edit >> Scaler Fields>> Z to SF
Edit >> Scaler Fields>> filter by value
use (0.0 to 0.2) (0.2 to 0.4) etc

Tools >> fit >> 2D polygon (facet)
use (0.5)
find area of new 2Dplygon from Edit >> Mesh >> measure surface

Attached raw mesh for trials
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raw.zip
(43.15 KiB) Downloaded 330 times
DA523
Posts: 166
Joined: Mon May 25, 2020 4:02 pm

Re: Obtaining cross sectional area and/or width along axis

Post by DA523 »

attached AutoHotkey script to cross-section in z
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123.zip
(1.86 MiB) Downloaded 530 times
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1920-1080-150percent-mouse 2.zip
(645 Bytes) Downloaded 500 times
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