# Problem in viewing segmentation volume and voronoi model

**URL:** <https://discourse.slicer.org/t/problem-in-viewing-segmentation-volume-and-voronoi-model/12144>\
**Category:** Support\
**Tags:** vmtk, centerlines\
**Created:** [June 21, 2020, 4:11pm UTC](https://discourse.slicer.org/t/problem-in-viewing-segmentation-volume-and-voronoi-model/12144 "2020-06-21T16:11:07Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Deepa](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/deepa/32/5634_2.png) [@Deepa](https://discourse.slicer.org/u/Deepa)\
**Post date:** [June 21, 2020, 4:11pm UTC](https://discourse.slicer.org/t/problem-in-viewing-segmentation-volume-and-voronoi-model/12144/1 "2020-06-21T16:11:07Z")

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Hello Everyone,  
I’m trying out the features of `Extract centerlines` available in recent Preview release.

In the Windows version, I could view both centerline and Voronoi model after hitting `Apply` (steps followed from [here](https://discourse.slicer.org/t/new-module-extract-centerline-in-slicervmtk-extension/12117)) . I am not able to view the Voronoi model in Linux version though.  
 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/e/b/eb895fcb45008999a1d53623ccb223f6bc01625b.png) .

The problem is after using `Extract Centerlines` I am not able to view the Voronoi model and segmentation volume (this can be seen in the snapshot posted above – the eye icon next to the segmentation node is open in the bottom image from Linux version).

Please note: The segmentation volume is visible after loading the file i.e prior to centerline computation. The volume disappears after hitting Apply in `Extract Centerlines` .

I have also tried to view the segmentation volume outside `VMTK` module, in the segment editor. It works absolutely fine and I am able to view the volume.

 ![Untitled](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/8/0/8017d1b2a59f06e93fb14ea8fad5da63727c5ddc.png)

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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:** [June 21, 2020, 4:42pm UTC](https://discourse.slicer.org/t/problem-in-viewing-segmentation-volume-and-voronoi-model/12144/2 "2020-06-21T16:42:24Z")

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Do the models appear correctly if you set their opacity to 1.0 (fully opaque)?  
Does disabling depth peeling make everything appear?  
How many points and cells are in the Voronoi model? (you can see it in the Models module Information section).

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**Author:** ![Deepa](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/deepa/32/5634_2.png) [@Deepa](https://discourse.slicer.org/u/Deepa)\
**Post date:** [June 22, 2020, 2:47am UTC](https://discourse.slicer.org/t/problem-in-viewing-segmentation-volume-and-voronoi-model/12144/3 "2020-06-22T02:47:11Z")

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@lassoan  
Thanks a lot for the response.

> [@lassoan](#):
>
> Do the models appear correctly if you set their opacity to 1.0 (fully opaque)?

Yes. The Voronoi model is visible only at 1. It is not visible for any value \<1 even after disabling depth peeling. There is no issue with the Windows version.

> [@lassoan](#):
>
> Does disabling depth peeling make everything appear?

No

> [@lassoan](#):
>
> How many points and cells are in the Voronoi model? (you can see it in the Models module Information section).

170983 .

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<div class="post-metadata">

**Author:** ![Deepa](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/deepa/32/5634_2.png) [@Deepa](https://discourse.slicer.org/u/Deepa)\
**Post date:** [June 23, 2020, 12:16pm UTC](https://discourse.slicer.org/t/problem-in-viewing-segmentation-volume-and-voronoi-model/12144/4 "2020-06-23T12:16:24Z")

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May I know if any update is available on this issue?

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<div class="post-metadata">

**Author:** ![Deepa](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/deepa/32/5634_2.png) [@Deepa](https://discourse.slicer.org/u/Deepa)\
**Post date:** [July 11, 2020, 7:47am UTC](https://discourse.slicer.org/t/problem-in-viewing-segmentation-volume-and-voronoi-model/12144/5 "2020-07-11T07:47:58Z")

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This problem persists even in the latest preview release. Immediately after centerline model is generated  
the 3D geometry disappears and voronoi model is visible only at opacity =1. This makes it really difficult for tasks like branch deletion. I never faced these issues in the releases made in June.

Could you please look into this?