# Can I use a spherical brush to select the edges of a mesh in a three-dimensional window?

**URL:** https://discourse.slicer.org/t/can-i-use-a-spherical-brush-to-select-the-edges-of-a-mesh-in-a-three-dimensional-window/8167
**Category:** Development
**Created:** [August 25, 2019, 11:59am UTC](https://discourse.slicer.org/t/can-i-use-a-spherical-brush-to-select-the-edges-of-a-mesh-in-a-three-dimensional-window/8167 "2019-08-25T11:59:10Z")
**Posts on this page:** 6
**Page:** 1

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### Author: ![timeanddoctor](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/timeanddoctor/32/5839_2.png) [@timeanddoctor](https://discourse.slicer.org/u/timeanddoctor)
#### Post date: [August 25, 2019, 11:59am UTC](https://discourse.slicer.org/t/can-i-use-a-spherical-brush-to-select-the-edges-of-a-mesh-in-a-three-dimensional-window/8167/1 "2019-08-25T11:59:10Z")

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Can I use a spherical brush to select the edges(mark the surface) of a mesh in a three-dimensional window?

 ![38](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/2/3/237dae5b62f6d7ee3fbce8060e9efbf63806e601.jpeg) ![39](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/5/6/561c65b37536e323606c1a0a9bc2a1a7e23e52b1.jpeg)

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### Author: ![JanWitowski](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/janwitowski/32/4512_2.png) [@JanWitowski](https://discourse.slicer.org/u/JanWitowski)
#### Post date: [August 25, 2019, 1:22pm UTC](https://discourse.slicer.org/t/can-i-use-a-spherical-brush-to-select-the-edges-of-a-mesh-in-a-three-dimensional-window/8167/2 "2019-08-25T13:22:43Z")

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Could you clarify what do you mean by marking the surface and what you are trying to achieve?

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### Author: ![timeanddoctor](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/timeanddoctor/32/5839_2.png) [@timeanddoctor](https://discourse.slicer.org/u/timeanddoctor)
#### Post date: [August 25, 2019, 1:54pm UTC](https://discourse.slicer.org/t/can-i-use-a-spherical-brush-to-select-the-edges-of-a-mesh-in-a-three-dimensional-window/8167/3 "2019-08-25T13:54:29Z")

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I want select the red area of the tumor just like the screen what I did in 3-matic by mark tool.

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### Author: ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)
#### Post date: [August 25, 2019, 2:06pm UTC](https://discourse.slicer.org/t/can-i-use-a-spherical-brush-to-select-the-edges-of-a-mesh-in-a-three-dimensional-window/8167/4 "2019-08-25T14:06:10Z")

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This is called Scissors effect in Segment Editor.

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### Author: ![timeanddoctor](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/timeanddoctor/32/5839_2.png) [@timeanddoctor](https://discourse.slicer.org/u/timeanddoctor)
#### Post date: [August 25, 2019, 2:24pm UTC](https://discourse.slicer.org/t/can-i-use-a-spherical-brush-to-select-the-edges-of-a-mesh-in-a-three-dimensional-window/8167/5 "2019-08-25T14:24:13Z")

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![41](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/0/6/063bda2d06e05ca259d43f8e75490c1db1b1030b.jpeg)

I can get the edge by follow steps:  
1.segment the tumor  
2.hollow  
3.crop the hollow by scissors many times

So can I do it just paint like this pictrue.  
 ![42](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/0/5/0505f6399d98eb6a09826fd3e6aeee8f42463228.jpeg)

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### Author: ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)
#### Post date: [August 25, 2019, 4:01pm UTC](https://discourse.slicer.org/t/can-i-use-a-spherical-brush-to-select-the-edges-of-a-mesh-in-a-three-dimensional-window/8167/6 "2019-08-25T16:01:02Z")

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I don’t think I understand what you mean. Can you explain what you are trying to achieve?