# Trim/Split Brep with a Curve C++ SDK

**URL:** <https://discourse.mcneel.com/t/trim-split-brep-with-a-curve-c-sdk/49043>\
**Category:** Rhino Developer\
**Created:** [November 9, 2017, 1:14pm UTC](https://discourse.mcneel.com/t/trim-split-brep-with-a-curve-c-sdk/49043 "2017-11-09T13:14:58Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![dimcic](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/dimcic/32/493194_2.png) [@dimcic](https://discourse.mcneel.com/u/dimcic)\
**Post date:** [November 9, 2017, 1:14pm UTC](https://discourse.mcneel.com/t/trim-split-brep-with-a-curve-c-sdk/49043/1 "2017-11-09T13:14:58Z")

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Hi,

this is a pretty basic question, and I think there is a simple answer for RhinoCommon, but I haven`t found the satisfying solution for C++. So, if I have a (closed) curve projected onto a brep, and I want to trim or split the Brep, I basically found two functions:

1. RhinoBrepSplit - this takes ON\_Brep as a “splitter” argument, so I have to extrude or do something else with the Curve to transform it into a Brep before I can split the original Brep, which complicates the matter significantly…

2. RhinoBrepTrim - I do not really understand the documentation and the implementation of this function and it seems like it also takes ON\_Brep as the “cutter”…

So what would be the simples way?

Thanks!

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**Author:** ![rajaa](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/rajaa/32/770789_2.png) [@rajaa](https://discourse.mcneel.com/u/rajaa)\
**Post date:** [November 9, 2017, 6:05pm UTC](https://discourse.mcneel.com/t/trim-split-brep-with-a-curve-c-sdk/49043/2 "2017-11-09T18:05:12Z")

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Try “RhinoSplitBrepFace”

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**Author:** ![dale](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/dale/32/685184_2.png) [@dale](https://discourse.mcneel.com/u/dale)\
**Post date:** [November 9, 2017, 6:26pm UTC](https://discourse.mcneel.com/t/trim-split-brep-with-a-curve-c-sdk/49043/3 "2017-11-09T18:26:33Z")

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Hi @dimcic,

The Rhino SDK does not have a function that splits a Brep with a curve. Do do this, extrude the curve through the Brep and then use `RhinoBrepSplit`.

– Dale