# Extract Solids from Surface issue

**URL:** <https://forum.dynamobim.com/t/extract-solids-from-surface-issue/105438>\
**Category:** Civil 3D\
**Tags:** geometry, dynamo\
**Created:** [October 28, 2024, 2:07pm UTC](https://forum.dynamobim.com/t/extract-solids-from-surface-issue/105438 "2024-10-28T14:07:05Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![denes.nagy](https://avatars.discourse-cdn.com/v4/letter/d/8e8cbc/32.png) [@denes.nagy](https://forum.dynamobim.com/u/denes.nagy)\
**Post date:** [October 28, 2024, 2:07pm UTC](https://forum.dynamobim.com/t/extract-solids-from-surface-issue/105438/1 "2024-10-28T14:07:05Z")

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Hi,

I have 2 dense TIN surfaces and with C3D’s Extract Solid from Surface function I cannot generate solids between them (perhaps it caused by the high density).

I’ve started to create the solids from Dynamo geometries, but I got stuck at the first step. I wanted to produce a vertical surface out of the extracted boundaries (3D polylines) of the TIN surfaces with Surface.ByLoft node, but nothing happened. The X,Y position of the 2 boundaries are the same.

Do you have any experience in this topic?

 ![image](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/9/4/9420a3d1062c67e2557f66cd69763497aab820cb.png)