# Bug - Boolean operation failed joining two simple bodies

**URL:** <https://discourse.shapr3d.com/t/bug-boolean-operation-failed-joining-two-simple-bodies/33530>\
**Category:** Modeling Questions\
**Created:** [September 1, 2024, 12:47pm UTC](https://discourse.shapr3d.com/t/bug-boolean-operation-failed-joining-two-simple-bodies/33530 "2024-09-01T12:47:54Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![qmpma1](https://avatars.discourse-cdn.com/v4/letter/q/85f322/32.png) [@qmpma1](https://discourse.shapr3d.com/u/qmpma1)\
**Post date:** [September 1, 2024, 12:47pm UTC](https://discourse.shapr3d.com/t/bug-boolean-operation-failed-joining-two-simple-bodies/33530/1 "2024-09-01T12:47:54Z")

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Hi, new to the forum and have not used shapr3d for long. Have generated various models and worked through any issues up to now.

Trying to union a simple 3d elipse with a simple 3d cylinder and Boolean operation fails. (Imagine a head inserting a neck into it).

 ![IMG_0259](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/2/9/29708dbbdb8b11b1f095246d058f3b8ac883d603.jpeg)

Can’t see anything obvious.  
Have included ,the very simple shapr3d file.  
Any help or questions welcome.

[Head.shapr](https://discourse.shapr3d.com/uploads/short-url/ikq1bydHYEGwLmoZLQYxPMkaK9B.shapr) (17.5 KB)

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**Author:** ![Bob3DPO](https://avatars.discourse-cdn.com/v4/letter/b/7993a0/32.png) [@Bob3DPO](https://discourse.shapr3d.com/u/Bob3DPO)\
**Post date:** [September 1, 2024, 1:27pm UTC](https://discourse.shapr3d.com/t/bug-boolean-operation-failed-joining-two-simple-bodies/33530/2 "2024-09-01T13:27:48Z")

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Hi Paul,

It looks like you found a bug. Suggest you change the title of your post and add “BUG” to it. The Shapr3D team follows this forum and that will help get their attention.

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**Author:** ![qmpma1](https://avatars.discourse-cdn.com/v4/letter/q/85f322/32.png) [@qmpma1](https://discourse.shapr3d.com/u/qmpma1)\
**Post date:** [September 1, 2024, 2:06pm UTC](https://discourse.shapr3d.com/t/bug-boolean-operation-failed-joining-two-simple-bodies/33530/3 "2024-09-01T14:06:26Z")

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Thank you, I had sent a support request via Shapr3d (before I posted, but thought I may get a quicker fix by posting), so it has been sent, but have also added Bug as you suggested.

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**Author:** ![jean-philippe2](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/jean-philippe2/32/27353_2.png) [@jean-philippe2](https://discourse.shapr3d.com/u/jean-philippe2)\
**Post date:** [September 1, 2024, 4:41pm UTC](https://discourse.shapr3d.com/t/bug-boolean-operation-failed-joining-two-simple-bodies/33530/4 "2024-09-01T16:41:15Z")

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Hi,  
I think it’s not a bug !  
Make Revolution on half oval et “le tour est joué”  
See screeenshot

 ![screen1](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/0/5/05e9a65dead299686cc26ac8d8d59db1fd5a69db.jpeg)

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<div class="post-metadata">

**Author:** ![Bob3DPO](https://avatars.discourse-cdn.com/v4/letter/b/7993a0/32.png) [@Bob3DPO](https://discourse.shapr3d.com/u/Bob3DPO)\
**Post date:** [September 1, 2024, 5:08pm UTC](https://discourse.shapr3d.com/t/bug-boolean-operation-failed-joining-two-simple-bodies/33530/5 "2024-09-01T17:08:17Z")

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Your work-around is fine. However, not being able to union those two bodies is a bug.

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<div class="post-metadata">

**Author:** ![qmpma1](https://avatars.discourse-cdn.com/v4/letter/q/85f322/32.png) [@qmpma1](https://discourse.shapr3d.com/u/qmpma1)\
**Post date:** [September 1, 2024, 6:51pm UTC](https://discourse.shapr3d.com/t/bug-boolean-operation-failed-joining-two-simple-bodies/33530/6 "2024-09-01T18:51:08Z")

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Merci beaucoup (and the fillet looks good) - workaround worked thanks.  
The fact this worked may help them fix the bug…  
Thanks all.

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**Author:** ![PEC](https://avatars.discourse-cdn.com/v4/letter/p/67e7ee/32.png) [@PEC](https://discourse.shapr3d.com/u/PEC)\
**Post date:** [September 2, 2024, 12:18pm UTC](https://discourse.shapr3d.com/t/bug-boolean-operation-failed-joining-two-simple-bodies/33530/7 "2024-09-02T12:18:18Z")

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Hi,

the root bug is in the first revolve, which generates non manifold bodies (meaning bodies with zero width like an infinitely thin sheet of paper instead of solid bodies) when you revolve a surface which is not half the section. Then boolean operations fails because the first body is invalid.

Add a breakpoint after the first revolve and edit the revolution angle to say +120°, -120° will show what I mean. Trying to set back 360° even leads to a different and invalid result.

Definitively a bug in the revolve tool: the sw should refuse to do the revolve in this case and should never create such non manifold body.  
The only valid way to use the revolve tool is with half cross sections as @jean-philippe2 suggested.