# Why Some Curves Create PlanarSrf and Some Do Not?

**URL:** <https://discourse.mcneel.com/t/why-some-curves-create-planarsrf-and-some-do-not/208348>\
**Category:** Rhino\
**Tags:** windows\
**Created:** [August 11, 2025, 6:15pm UTC](https://discourse.mcneel.com/t/why-some-curves-create-planarsrf-and-some-do-not/208348 "2025-08-11T18:15:22Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![Jonathan\_Ive](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/jonathan_ive/32/656105_2.png) [@Jonathan\_Ive](https://discourse.mcneel.com/u/Jonathan_Ive)\
**Post date:** [August 11, 2025, 6:15pm UTC](https://discourse.mcneel.com/t/why-some-curves-create-planarsrf-and-some-do-not/208348/1 "2025-08-11T18:15:22Z")

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Hey there,

I have a problem (picture attached). I use PlanarSrf command to create planar surfaces but with this particular case for some reason with situation captioned as 2 PlanarSrf detects inner boundaries and with sutuation 1 it does not. What could be the problem? I checked and pretty sure every curve is planar and closed.

 ![Screenshot 2025-08-11 211034](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/d/9/6/d96e07ac8bb6d625432972a696008f08d03924d7.png)

UPD: I discovered that the issue might be that with the situation 1 the outer boundary is curve and the inner is polyline. Apparently you can’t create PlanarSrf that way. Is there workaround for this problem?

Thank you in advance.

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**Author:** ![Gijs](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/gijs/32/769882_2.png) [@Gijs](https://discourse.mcneel.com/u/Gijs)\
**Post date:** [August 11, 2025, 6:48pm UTC](https://discourse.mcneel.com/t/why-some-curves-create-planarsrf-and-some-do-not/208348/2 "2025-08-11T18:48:01Z")

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The curve at 1 is either not planar, not closed or both. Can you send the file?

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**Author:** ![encephalon](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/encephalon/32/611970_2.png) [@encephalon](https://discourse.mcneel.com/u/encephalon)\
**Post date:** [August 11, 2025, 7:27pm UTC](https://discourse.mcneel.com/t/why-some-curves-create-planarsrf-and-some-do-not/208348/4 "2025-08-11T19:27:11Z")

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maybe selfintersecting, just post the geometry no more guesses needed?

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**Author:** ![Jonathan\_Ive](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/jonathan_ive/32/656105_2.png) [@Jonathan\_Ive](https://discourse.mcneel.com/u/Jonathan_Ive)\
**Post date:** [August 12, 2025, 2:18pm UTC](https://discourse.mcneel.com/t/why-some-curves-create-planarsrf-and-some-do-not/208348/5 "2025-08-12T14:18:39Z")

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Sorry, forgot to attache the file. And I also discovered that PlanarSrf command will work if I exclude some inner boundaries out of selection (shown on pictures).

 ![image](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/7/e/5/7e542b131aa12f41c8ed22ba6206b5670f5db8fb.png)

 ![image](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/6/7/2/67222caf885d7f9fc8f3e0ca59d6996bd51a92ae.png)

Thank you in advance.

[PlanarSrf Issue.3dm](https://discourse.mcneel.com/uploads/short-url/avrL72AF0AhGdkQockIsyJYhpLn.3dm) (126.8 KB)

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<div class="post-metadata">

**Author:** ![Gijs](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/gijs/32/769882_2.png) [@Gijs](https://discourse.mcneel.com/u/Gijs)\
**Post date:** [August 12, 2025, 2:35pm UTC](https://discourse.mcneel.com/t/why-some-curves-create-planarsrf-and-some-do-not/208348/6 "2025-08-12T14:35:32Z")

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thanks for the file. At tolerance 0.1 the result is as expected.

[RH-88817](https://mcneel.myjetbrains.com/youtrack/issue/RH-88817) PlanarSrf from curves fails

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<div class="post-metadata">

**Author:** ![Jonathan\_Ive](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/jonathan_ive/32/656105_2.png) [@Jonathan\_Ive](https://discourse.mcneel.com/u/Jonathan_Ive)\
**Post date:** [August 12, 2025, 6:18pm UTC](https://discourse.mcneel.com/t/why-some-curves-create-planarsrf-and-some-do-not/208348/7 "2025-08-12T18:18:56Z")

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It really does work that way. Thank you so much.