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Distinguished Contributor
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Registered: ‎11-06-2006

Volume calculation for 3D Faces object

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01-09-2013 11:00 AM

Hi:

I have a volume in my CAD file described by 3D Faces. Is there anyway to know what is the volume of this volume -that represents an open pit-?

Every time that I do a volume I do by the comparison of 2 surfaces but this is not the case now.

Rafael

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Re: Volume calculation for 3D Faces object

01-09-2013 11:14 AM in reply to: RafaelMoreno

in order to get the volume of a pond for instance if it is filled to elevation 979.00

a flat surface using a rectangle with elevation 979 which is larger than the pond is used to compare to the pond surface.

does this make sense?

Dan

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Re: Volume calculation for 3D Faces object

01-09-2013 11:24 AM in reply to: RafaelMoreno

Do the 3D faces represent the pit, or the volume of the pit?  The way you wrote it makes me think the latter.  Where did they come from?  It is possible that a Volume surface was exploded or had the 3D faces extracted from it.  If that is the case, you need to build a surface from the 3D faces and another surface at elevation zero, and compare the two.

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Distinguished Contributor
Posts: 184
Registered: ‎11-06-2006

Re: Volume calculation for 3D Faces object

01-09-2013 01:36 PM in reply to: troma

Hi Troma, thanks for your long replay:

The 3D faces that I have represent the Pit. So trying to to clean the file in order to get the 3D faces that represent the surface of the pit is almost....impossible.

There is not way tof calculating the volume taking the 3D faces in the way I am describing?

Thanks

Rafael

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Re: Volume calculation for 3D Faces object

01-09-2013 07:54 PM in reply to: RafaelMoreno
Civil 3D only calculates volumes using surfaces. You'll need to create surfaces and then calculate volumes. I doubt AutoCAD itself can do any such volume calculation.
Matt Kolberg
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Re: Volume calculation for 3D Faces object

01-10-2013 05:27 AM in reply to: RafaelMoreno

What do you mean about 'Cleaning' the file?

If you have 3D faces that represent the pit, you can use them to build a TIN surface that duplicates them exactly.

Then you need to create another surface at the top of the pit.  That will either be flat, as described earlier by others, or you could match it to the top of slope of the pit.

You can then calculate a volume between the two surfaces.

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Distinguished Contributor
Posts: 184
Registered: ‎11-06-2006

Re: Volume calculation for 3D Faces object

01-11-2013 11:38 AM in reply to: troma

Hi:

Thanks for the solution. I was lucky that the file came not only with the Volume that descrbed the pit but also with the Surface that described the same pit in a different layer, then I build the surface so I can now calculate the volume comparing this surface with the Original Ground surface

Regards

Rafael