# Segmentation in volume rendering mode

**URL:** <https://discourse.slicer.org/t/segmentation-in-volume-rendering-mode/40693>\
**Category:** Support\
**Created:** [December 14, 2024, 9:08am UTC](https://discourse.slicer.org/t/segmentation-in-volume-rendering-mode/40693 "2024-12-14T09:08:11Z")\
**Posts on this page:** 10\
**Page:** 1

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**Author:** ![alex\_He](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/alex_he/32/67616_2.png) [@alex\_He](https://discourse.slicer.org/u/alex_He)\
**Post date:** [December 14, 2024, 9:08am UTC](https://discourse.slicer.org/t/segmentation-in-volume-rendering-mode/40693/1 "2024-12-14T09:08:11Z")

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Hi I am trying to do segmentation in 3d view in volume rendering mode but failed, any advise?

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**Author:** ![muratmaga](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/muratmaga/32/3622_2.png) [@muratmaga](https://discourse.slicer.org/u/muratmaga)\
**Post date:** [December 15, 2024, 2:26am UTC](https://discourse.slicer.org/t/segmentation-in-volume-rendering-mode/40693/2 "2024-12-15T02:26:09Z")

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You cannot visualize segmentations with volume rendering. Segmentations are shown as 3D closed surface representation (models). Hit the the Show 3D button to visualize your segments. Or see the user documentation [https://slicer.readthedocs.io](https://slicer.readthedocs.io) (and scroll down to segmentation link).

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**Author:** ![alex\_He](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/alex_he/32/67616_2.png) [@alex\_He](https://discourse.slicer.org/u/alex_He)\
**Post date:** [December 15, 2024, 9:25am UTC](https://discourse.slicer.org/t/segmentation-in-volume-rendering-mode/40693/3 "2024-12-15T09:25:53Z")

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Thanks for your advise, but I need to cutoff some parts in the volume rendering 3d view to see more insight of the volume, could you please advise me how to do it?

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**Author:** ![muratmaga](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/muratmaga/32/3622_2.png) [@muratmaga](https://discourse.slicer.org/u/muratmaga)\
**Post date:** [December 15, 2024, 1:49pm UTC](https://discourse.slicer.org/t/segmentation-in-volume-rendering-mode/40693/4 "2024-12-15T13:49:15Z")

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You can use the crop option in the volume rendering to cut your volume.

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<div class="post-metadata">

**Author:** ![alex\_He](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/alex_he/32/67616_2.png) [@alex\_He](https://discourse.slicer.org/u/alex_He)\
**Post date:** [December 16, 2024, 5:08am UTC](https://discourse.slicer.org/t/segmentation-in-volume-rendering-mode/40693/5 "2024-12-16T05:08:30Z")

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Thanks for your advise, I will try it out.

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**Author:** ![alex\_He](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/alex_he/32/67616_2.png) [@alex\_He](https://discourse.slicer.org/u/alex_He)\
**Post date:** [December 16, 2024, 1:07pm UTC](https://discourse.slicer.org/t/segmentation-in-volume-rendering-mode/40693/6 "2024-12-16T13:07:38Z")

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Hi after some trying , i notice that the crop options can only allow me to crop the volume with the rectangular crop box, but I need to crop the volume using a free enclosed surface , not the rectangular box. Or i need to trim the crop box to some other shape like wedge shape, please advise further.

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**Author:** ![cpinter](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/cpinter/32/7995_2.png) [@cpinter](https://discourse.slicer.org/u/cpinter)\
**Post date:** [December 16, 2024, 1:17pm UTC](https://discourse.slicer.org/t/segmentation-in-volume-rendering-mode/40693/7 "2024-12-16T13:17:25Z")

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I think in the current Slicer version the best option you have is to use the Mask volume effect in Segment Editor. Create a segment (I suggest starting with using Scissors in 3D) that contains the part you want to keep, then go to the Mask volume tool, enter the background value (e.g. -3000 for CT), then click Apply. Now volume render the masked volume.

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/1/d/1dd8fb0e04ceb668352d90474f22f63e36682baa.png)

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**Author:** ![alex\_He](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/alex_he/32/67616_2.png) [@alex\_He](https://discourse.slicer.org/u/alex_He)\
**Post date:** [December 16, 2024, 1:23pm UTC](https://discourse.slicer.org/t/segmentation-in-volume-rendering-mode/40693/8 "2024-12-16T13:23:26Z")

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Thanks, but I do not fully understand what you said, could you please explain a little more detail?

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<div class="post-metadata">

**Author:** ![cpinter](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/cpinter/32/7995_2.png) [@cpinter](https://discourse.slicer.org/u/cpinter)\
**Post date:** [December 16, 2024, 1:25pm UTC](https://discourse.slicer.org/t/segmentation-in-volume-rendering-mode/40693/9 "2024-12-16T13:25:18Z")

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I see you only saw the email. Please go to the forum page, I added a screenshot after submitting the comment.

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**Author:** ![alex\_He](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/alex_he/32/67616_2.png) [@alex\_He](https://discourse.slicer.org/u/alex_He)\
**Post date:** [December 16, 2024, 1:48pm UTC](https://discourse.slicer.org/t/segmentation-in-volume-rendering-mode/40693/10 "2024-12-16T13:48:29Z")

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Ok , I got you, will try tomorrow. Thanks