# Extruding polygon to circle

**URL:** <https://discourse.shapr3d.com/t/extruding-polygon-to-circle/40563>\
**Category:** Modeling Questions\
**Created:** [March 29, 2026, 5:29pm UTC](https://discourse.shapr3d.com/t/extruding-polygon-to-circle/40563 "2026-03-29T17:29:17Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![msibleyj](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/msibleyj/32/29845_2.png) [@msibleyj](https://discourse.shapr3d.com/u/msibleyj)\
**Post date:** [March 29, 2026, 5:29pm UTC](https://discourse.shapr3d.com/t/extruding-polygon-to-circle/40563/1 "2026-03-29T17:29:17Z")

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I’m trying to morph the shape of this polygon to a circle. Nothing seems to work. I need to keep the bottom section intact but make the top of the polygon shape change dimensions to fit the bottom of the circular shape. I’d settle for going to a square shape if this isn’t possible.

Thanks in advance,  
Mark

 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/1/0/10c6d68a4726eb75fe99e15e9820c7fdfbb78e30.png)

[Cord Plug.shapr](https://discourse.shapr3d.com/uploads/short-url/tNTHum0UUOvBVXAAyf4CKKuukqG.shapr) (15.5 MB)

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**Author:** ![Xdrakosha](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/xdrakosha/32/24881_2.png) [@Xdrakosha](https://discourse.shapr3d.com/u/Xdrakosha)\
**Post date:** [March 29, 2026, 5:51pm UTC](https://discourse.shapr3d.com/t/extruding-polygon-to-circle/40563/2 "2026-03-29T17:51:27Z")

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**Author:** ![msibleyj](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/msibleyj/32/29845_2.png) [@msibleyj](https://discourse.shapr3d.com/u/msibleyj)\
**Post date:** [March 29, 2026, 6:29pm UTC](https://discourse.shapr3d.com/t/extruding-polygon-to-circle/40563/3 "2026-03-29T18:29:23Z")

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Excellent. Thanks so much for the video. I was able to follow step-by-step. I almost missed the Shell function at the end, but figured it out.

Thanks again,  
Mark

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**Author:** ![Xdrakosha](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/xdrakosha/32/24881_2.png) [@Xdrakosha](https://discourse.shapr3d.com/u/Xdrakosha)\
**Post date:** [March 29, 2026, 6:47pm UTC](https://discourse.shapr3d.com/t/extruding-polygon-to-circle/40563/4 "2026-03-29T18:47:13Z")

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> [@msibleyj](#):
>
> I almost missed the Shell function at the end

Always look at the top, you can see current active tool there.

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**Author:** ![Arbuthnott](https://avatars.discourse-cdn.com/v4/letter/a/9fc348/32.png) [@Arbuthnott](https://discourse.shapr3d.com/u/Arbuthnott)\
**Post date:** [March 31, 2026, 8:27am UTC](https://discourse.shapr3d.com/t/extruding-polygon-to-circle/40563/5 "2026-03-31T08:27:47Z")

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You may want to do something more complex than can be reflected by doing just SHELL at the end. If you do a slice through both of those two shapes vertically separating out say the right hand side from the left-hand side of both of those two shapes and then do a loft between the left-hand lower and left-hand upper and the same with the right hand lower and the right hand upper you can have more complex profiles of the thickness of the underlying shape.

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**Author:** ![Xdrakosha](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/xdrakosha/32/24881_2.png) [@Xdrakosha](https://discourse.shapr3d.com/u/Xdrakosha)\
**Post date:** [March 31, 2026, 10:33am UTC](https://discourse.shapr3d.com/t/extruding-polygon-to-circle/40563/6 "2026-03-31T10:33:16Z")

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> [@Arbuthnott](#):
>
> you can have more complex profiles of the thickness of the underlying shape

I didn’t show this variant intentionally because the TC has the same thickness for both the bottom and the top pipes. However, here’s another approach that makes it easy to use different thicknesses.