# Stock Pile measures not consistent

Hi All,
I’m hoping you can help me out here. We are still working around this software and trying to learn and have found a couple of issues. Hope you can help us out? Thanks in advance.

Question 1

I have a question when it come to comparing volumes month to month,

When doing a stockpile calc what is the over all Volume?
Is it the cut volume or the bottom line, these tend to change quite a bit so it hard to get consistency? See Pic 1

Question 2

Trying to work out how much material have been placed in the below area month to month.

In the above link is says, if the base vertices are known you can import a .shp file? (link below)

Is this where you can do a surface-to-surface calc?
Or maybe I’m wrong and a .shp file is not a surface.

If this is a surface, this would be best for month-to-month changes volume calcs.

Area of clean Fill – Back Fill. Pic 2

Summary

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Hi, thank you for your question.

I replied to your direct support ticket but I’m also copying my result here in order to help other customers as well.

Question 1

The volume calculated by PIX4Dcloud is defined by a base surface (polygon) and the DSM.

• If the volume polygon is below the DSM, the volume is “cut”.
• If the volume polygon is above the DSM, the volume is “fill”.
• You can have both values if the volume polygon is partially above and partially below the DSM.
• “Volume difference” is the sum between “cut” and “fill”. Because “fill” has negative values, when “cut” and “fill” have similar absolute values, “Volume difference” tends to zero.

You see here that the role of the right base surface is important. You can learn more about the differences between the different methods here:

Question 2

Note that this tool is not calculating differences between dates but calculates the volume for each date and creates a table/spreadsheet.
You can then add the calculations you desire in the spreadsheet in order to get the data you want.

You can find some examples of interpretation here:

Note that this article refers to PIX4Dmapper but the way volume is measured is comparable.

Also, both link you shared are referring to PIX4Dmapper.