# Get curve on surface of brep

**URL:** <https://discourse.mcneel.com/t/get-curve-on-surface-of-brep/186704>\
**Category:** Grasshopper\
**Tags:** windows\
**Created:** [July 3, 2024, 9:58am UTC](https://discourse.mcneel.com/t/get-curve-on-surface-of-brep/186704 "2024-07-03T09:58:21Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![yan\_novikov](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/yan_novikov/32/585735_2.png) [@yan\_novikov](https://discourse.mcneel.com/u/yan_novikov)\
**Post date:** [July 3, 2024, 9:58am UTC](https://discourse.mcneel.com/t/get-curve-on-surface-of-brep/186704/1 "2024-07-03T09:58:21Z")

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Hello.  
I have the following problem: there is a curved surface built using two segments of a circle with different radius and different height position. I need to build a curve on the surface by two variants:

1. more complicated - with an offset (can be different) from the corners on the diagonal.
2. simple - from one corner to the other on the diagonal. In general, it is even clear that you can find the center of the curves, draw a line between them to find the middle of this curve, but what to do next, what tool to use I do not know.  
Maybe who has faced such a problem and knows the solution?  
 ![image](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/a/8/5/a8540aa36fdf770158fe235f9f9af8499c65158f.png)  
[Get\_curve\_on\_brep.gh](https://discourse.mcneel.com/uploads/short-url/lCXNvoQuifIM3lNhwZ0TCpVbciG.gh) (3.1 KB)

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**Author:** ![Rajeev2](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/rajeev2/32/631520_2.png) [@Rajeev2](https://discourse.mcneel.com/u/Rajeev2)\
**Post date:** [July 3, 2024, 10:50am UTC](https://discourse.mcneel.com/t/get-curve-on-surface-of-brep/186704/2 "2024-07-03T10:50:52Z")

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![image](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/0/3/0/030f03ddb466cc00c172c6b8c3afb75438c2ad43.png)

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**Author:** ![yan\_novikov](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/yan_novikov/32/585735_2.png) [@yan\_novikov](https://discourse.mcneel.com/u/yan_novikov)\
**Post date:** [July 4, 2024, 7:27am UTC](https://discourse.mcneel.com/t/get-curve-on-surface-of-brep/186704/3 "2024-07-04T07:27:36Z")

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Thank you for reply, but it doesn’t what i want to get.  
If we look at the result in the XZ plane, we see that the curve is stretched perpendicularly (along the normal) to the surface, whereas I need it to be stretched horizontally along the XY plane (then the lines will coincide in the XZ plane).  
 ![image](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/2/4/2/242d99b9d188e1254cceeef0d392be66346452e9.png)

 ![image](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/d/a/c/dac4b2703b8ab868524fb475c8c9d6c460510656.png)

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<div class="post-metadata">

**Author:** ![Rajeev2](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/rajeev2/32/631520_2.png) [@Rajeev2](https://discourse.mcneel.com/u/Rajeev2)\
**Post date:** [July 4, 2024, 7:35am UTC](https://discourse.mcneel.com/t/get-curve-on-surface-of-brep/186704/4 "2024-07-04T07:35:39Z")

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![image](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/1/5/0/150effa2949d6656c962e03220340d14d601fe15.png)

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<div class="post-metadata">

**Author:** ![yan\_novikov](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/yan_novikov/32/585735_2.png) [@yan\_novikov](https://discourse.mcneel.com/u/yan_novikov)\
**Post date:** [July 4, 2024, 7:57am UTC](https://discourse.mcneel.com/t/get-curve-on-surface-of-brep/186704/5 "2024-07-04T07:57:39Z")

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I appreciate your prompt replies 🙏. But it seems that I don’t understand final result clearly myself which i want. 😀 I’ll come back later with an understanding of what the line should be on the surface