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About Volume calculation Results
Posted: Mon Jun 17, 2024 9:11 am
by SAYURI
hello
The following calculation results were obtained using '2.5D Volume calculation tool'.
Volume: 63.964
Surface: 51.463
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Added volume: (+)64.839
Removed volume: (-)0.875
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Matching cells: 94.0%
Non-matching cells:
ground = 5.5%
ceil = 0.5%
Average neighbors per cell: 8.0 / 8.0
To get close to the correct volume, should Matching cells be close to 100% and Non-matching cells be close to 0%?
Or is there something more important?
Re: About Volume calculation Results
Posted: Tue Jun 18, 2024 11:15 am
by DA523
Most of the time, but not all the cases, optimum volume and area is when % of matching cells is close to % of shape area to area of containing rectangular (min x min y, max x max y)
and it is tricky
You can use try and error or visual inspection
Usually, you start with samll grid and increase till you get constant volume
- Screenshot_2024-06-18-13-57-30-113_com.simplemobiletools.draw.pro.jpg (40.62 KiB) Viewed 220 times
Re: About Volume calculation Results
Posted: Tue Jun 18, 2024 8:56 pm
by TobyAdam
Yes, to achieve accurate volume calculations, having Matching cells close to 100% and Non-matching cells close to 0% is crucial, as it indicates a high level of correspondence between the calculated and actual volumes. However, also consider the precision of the tool and the data quality used in the calculation.
Re: About Volume calculation Results
Posted: Tue Jun 18, 2024 9:02 pm
by daniel
Well, matching and non-matching cells mostly indicate that the overlap between the 2 clouds is not 100%
What's most important is the 'Average neighbors per cell' (maximum is 8 - any lower value indicates that there might be holes, so potentially missing points between 2 cells, and thus probably a too small step value). Ideally it should be above 7.
But I like the process described by DA523, by reducing the step value step by step and look for a stable volume estimation.
Re: About Volume calculation Results
Posted: Wed Jun 19, 2024 2:48 am
by SAYURI
DA523, the diagram is very helpful. Thank you for the easy-to-understand diagram and explanation.
TobyAdam, thank you for calling attention to quality.
daniel, I missed the important point in Results. thank you for teaching me.
I adjust the 'step' and note the Results.
I'm happy to get closer to getting the correct values.
Re: About Volume calculation Results
Posted: Wed Jun 19, 2024 9:50 pm
by DA523
Take care !!
2.5d volume has limitations
Please check the attached example where 2.5d volume fails because 2 z levels in the same pointscloud
real volume=2.964 cubic units
- Screenshot (308).png (90.41 KiB) Viewed 133 times