# Mirroring 2d shapes gives me "invalid selection"

**URL:** <https://discourse.shapr3d.com/t/mirroring-2d-shapes-gives-me-invalid-selection/22557>\
**Category:** Modeling Questions\
**Created:** [November 19, 2022, 11:40pm UTC](https://discourse.shapr3d.com/t/mirroring-2d-shapes-gives-me-invalid-selection/22557 "2022-11-19T23:40:28Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Iliketrains](https://avatars.discourse-cdn.com/v4/letter/i/b5ac83/32.png) [@Iliketrains](https://discourse.shapr3d.com/u/Iliketrains)\
**Post date:** [November 19, 2022, 11:40pm UTC](https://discourse.shapr3d.com/t/mirroring-2d-shapes-gives-me-invalid-selection/22557/1 "2022-11-19T23:40:28Z")

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Hi,

I am trying to draw 2d shapes, mirror them then use them to then extrude with.

I can mirror basic shapes like squares and rectangles.

Whenever I try to mirror anything I have made by connecting a few shapes (like a rectangle and a circle to get a rectangle with one curved end) I get “invalid selection” when I select the edge I want to mirror from.

I’ve since been attempting to exactly copy a few videos of people mirroring stuff and despite trying to recreate exactly what they have done I am still getting “invalid selection”

Help appreciated I’m currently stuck unable to progress unless I do very tedious and careful redrawing of everything I want to mirror.

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**Author:** ![Matt\_the-Rathje](https://avatars.discourse-cdn.com/v4/letter/m/49beb7/32.png) [@Matt\_the-Rathje](https://discourse.shapr3d.com/u/Matt_the-Rathje)\
**Post date:** [November 20, 2022, 12:19am UTC](https://discourse.shapr3d.com/t/mirroring-2d-shapes-gives-me-invalid-selection/22557/2 "2022-11-20T00:19:21Z")

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Hi Liketrains,  
it is alittle hard to help you without seeing the geometry you are working with.  
Basically all volume-modelling (Solid) CAD-software have issues with so called zero-geometry or zero-thickness.  
That means if you have a shape with a sharp vertex at the line of revolution - that relults in invalid geometry.  
Please help me to help you with some screenshots.  
Cheers Matt

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<div class="post-metadata">

**Author:** ![Iliketrains](https://avatars.discourse-cdn.com/v4/letter/i/b5ac83/32.png) [@Iliketrains](https://discourse.shapr3d.com/u/Iliketrains)\
**Post date:** [November 20, 2022, 12:54am UTC](https://discourse.shapr3d.com/t/mirroring-2d-shapes-gives-me-invalid-selection/22557/3 "2022-11-20T00:54:06Z")

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![PXL_20221120_004751077](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/1/c/1c5876569a5b77017cec1b3fd5c86a7b1df152b1.jpeg)

In the attached image, I have drawn a rectangle, an arc and then removed some lines to create an irregular shape.

I can mirror the rectangle but I cannot always mirror the end product after Ive added a curve to it.

Checking again this behaviour seems to be inconsistent - drawing the shape by itself for the above screenshot just worked but drawing it in contact with the edge of the shape I want to extrude through gave me the same error message.

Drawing it in contact with the shape then moving it up a little then using the mirror tool also worked - looks like I have a solution of sorts there it’s just going to require more steps.