# Moving spline points on Z plane?

**URL:** <https://discourse.shapr3d.com/t/moving-spline-points-on-z-plane/12313>\
**Category:** Modeling Questions\
**Created:** [April 16, 2021, 5:18pm UTC](https://discourse.shapr3d.com/t/moving-spline-points-on-z-plane/12313 "2021-04-16T17:18:21Z")\
**Posts on this page:** 3\
**Page:** 2

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**Author:** ![milouchien](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/milouchien/32/10020_2.png) [@milouchien](https://discourse.shapr3d.com/u/milouchien)\
**Post date:** [April 22, 2021, 12:00am UTC](https://discourse.shapr3d.com/t/moving-spline-points-on-z-plane/12313/21 "2021-04-22T00:00:29Z")

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Yes that’s good. The helical segment is probably the only way to do those corners in Shapr at the moment. It’s a good thing you’re not using a pseudohelical quarter ellipse huh?!!

Do you agree a sweep tool where the top stays at the top would be useful? That and the 3d spline would solve all these problems. Might even be useful with the workaround “spline” I used before…

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**Author:** ![OserCAD](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/osercad/32/9390_2.png) [@OserCAD](https://discourse.shapr3d.com/u/OserCAD)\
**Post date:** [April 22, 2021, 5:36am UTC](https://discourse.shapr3d.com/t/moving-spline-points-on-z-plane/12313/22 "2021-04-22T05:36:22Z")

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AutoCAD has an option for a knotted spline, you are able to adjust the zed value of the control data points, and when applying a sweep about the path you get the option of twisting the profile, 0 rotation sets it same as what you start with. A 180 twist coming back to its start point would give you a möbius strip. It is tricky to control a spline to keep its normal orientation. Here is a three twist path, it would be cool to model this with this tool. Check out low temp physics experiment from Ithica College [https://youtu.be/Vxror-fnOL4](https://youtu.be/Vxror-fnOL4)

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**Author:** ![milouchien](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/milouchien/32/10020_2.png) [@milouchien](https://discourse.shapr3d.com/u/milouchien)\
**Post date:** [April 22, 2021, 6:27am UTC](https://discourse.shapr3d.com/t/moving-spline-points-on-z-plane/12313/23 "2021-04-22T06:27:18Z")

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Very interesting. So that might be considered a standard way of doing it. And by making the sweep in segments, you can achieve almost anything.

@Istvan the request I made for a controlled sweep is better described here by @OserCAD as an Autocad like sweep function.

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