# Mass from two toposurface

**URL:** <https://forum.dynamobim.com/t/mass-from-two-toposurface/95814>\
**Category:** Uncategorized\
**Created:** [November 24, 2023, 1:55pm UTC](https://forum.dynamobim.com/t/mass-from-two-toposurface/95814 "2023-11-24T13:55:35Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![paolo.campana](https://avatars.discourse-cdn.com/v4/letter/p/7cd45c/32.png) [@paolo.campana](https://forum.dynamobim.com/u/paolo.campana)\
**Post date:** [November 24, 2023, 1:55pm UTC](https://forum.dynamobim.com/t/mass-from-two-toposurface/95814/1 "2023-11-24T13:55:35Z")

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Hi all, i’m trying to understand the way to define a mass on the base of toposurface intersection, i have one topo defined the pre-construction state and a topo rapresenting the excavation, i need to extract the mass of the difference. Could someone put me in the right way?  
thanks

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**Author:** ![Drbohlav](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/drbohlav/32/113004_2.png) [@Drbohlav](https://forum.dynamobim.com/u/Drbohlav)\
**Post date:** [November 24, 2023, 2:56pm UTC](https://forum.dynamobim.com/t/mass-from-two-toposurface/95814/2 "2023-11-24T14:56:10Z")

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Hi @paolo.campana, what object is “toposurface” exactly and in what software? If you have any Dynamo graphs you’ve created so far, please attach them.

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**Author:** ![paolo.campana](https://avatars.discourse-cdn.com/v4/letter/p/7cd45c/32.png) [@paolo.campana](https://forum.dynamobim.com/u/paolo.campana)\
**Post date:** [November 24, 2023, 4:08pm UTC](https://forum.dynamobim.com/t/mass-from-two-toposurface/95814/3 "2023-11-24T16:08:01Z")

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Sorry…i forgot…software is revit…

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**Author:** ![Drbohlav](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/drbohlav/32/113004_2.png) [@Drbohlav](https://forum.dynamobim.com/u/Drbohlav)\
**Post date:** [November 24, 2023, 6:31pm UTC](https://forum.dynamobim.com/t/mass-from-two-toposurface/95814/4 "2023-11-24T18:31:31Z")

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What is the version of Revit? And surfaces are topography objects?

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**Author:** ![paolo.campana](https://avatars.discourse-cdn.com/v4/letter/p/7cd45c/32.png) [@paolo.campana](https://forum.dynamobim.com/u/paolo.campana)\
**Post date:** [November 26, 2023, 9:51am UTC](https://forum.dynamobim.com/t/mass-from-two-toposurface/95814/5 "2023-11-26T09:51:26Z")

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Revit 2023, surface are topography