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Calculating volume of scanned cylinder

Posted: Sun Aug 28, 2022 11:51 am
by W.Rutkowski
Hello,
I have a problem with calculating volume of scanned concrete lining in underground mine. What's the best method to calculate this kind of object? In the link below I attach point cloud created with iPhone 13Pro scanner.
I tried to use "compute 2.5D volume" yet results were far from expected. Volume for this object should be around 154m3.
Any help in this matter would be most appreciated!

Download link
https://wetransfer.com/downloads/ab4cf1 ... 751/1ac8d2

Re: Calculating volume of scanned cylinder

Posted: Thu Sep 01, 2022 9:11 pm
by daniel
Indeed, the 2.5D volume calculation tool cannot be used on this kind of cloud.

You'd better fit a cylinder to the cloud with the 'Ransac Shape Detection' plugin. Check only the 'cylinder' shape to be detected, and increase the minimum number of supporting points (from 500 to 50 000 for instance).

It will fit only one cylinder this way. You can find it below the resulting sub-clouds (there should only be one hopefully). You can then select the cylinder entity and use 'Edit > Mesh > Measure Volume'.

Re: Calculating volume of scanned cylinder

Posted: Thu Sep 01, 2022 9:54 pm
by DA523
cntl+t
rotate around Y by 90
calculate normal
normals to SF
filer by SF 0 to 1
find volume between the 2 new parts
it is around 157 cu
another way is to use Poisson meshing then fit -facet etc ...
Using Blender can help a lot
.
Screenshot (10).png
Screenshot (10).png (46.15 KiB) Viewed 1657 times

Re: Calculating volume of scanned cylinder

Posted: Thu Sep 01, 2022 10:05 pm
by DA523
Can I post 3D stl file here?

Re: Calculating volume of scanned cylinder

Posted: Fri Sep 02, 2022 8:18 pm
by daniel
I don't think the forum accepts stl files!