# Control point labels show through 3D volume in volume rendering

**URL:** <https://discourse.slicer.org/t/control-point-labels-show-through-3d-volume-in-volume-rendering/25517>\
**Category:** Support\
**Created:** [October 3, 2022, 4:58am UTC](https://discourse.slicer.org/t/control-point-labels-show-through-3d-volume-in-volume-rendering/25517 "2022-10-03T04:58:08Z")\
**Posts on this page:** 11\
**Page:** 1

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**Author:** ![Pheasant](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pheasant/32/15560_2.png) [@Pheasant](https://discourse.slicer.org/u/Pheasant)\
**Post date:** [October 3, 2022, 4:58am UTC](https://discourse.slicer.org/t/control-point-labels-show-through-3d-volume-in-volume-rendering/25517/1 "2022-10-03T04:58:09Z")

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Hi,

It would seem that the markup labels show through the 3D volume when using volume rendering. Is it possible to turn this off or is it a bug?

It gets very crowded with text and it is difficult to pinpoint the correct labels when they all can be constantly seen. I would like for the labels still to be there so they can be seen in the proper 2D slices and in the mark up module

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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:** [October 3, 2022, 5:17am UTC](https://discourse.slicer.org/t/control-point-labels-show-through-3d-volume-in-volume-rendering/25517/2 "2022-10-03T05:17:40Z")

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> [@Pheasant](#):
>
> 3D volume when using volum

I don’t think this is possible with the UI controls. If you are not actively collecting landmarks, one solution would be to clone the pointList and then use one copy for 2D display (where you can turn off the 3D visibility), and you set to the second copy to set to be visible only in 3D but bring down the text scaling to % (so the labels are not visible, only the glyphs).

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**Author:** ![Pheasant](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pheasant/32/15560_2.png) [@Pheasant](https://discourse.slicer.org/u/Pheasant)\
**Post date:** [October 3, 2022, 6:05am UTC](https://discourse.slicer.org/t/control-point-labels-show-through-3d-volume-in-volume-rendering/25517/3 "2022-10-03T06:05:16Z")

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In the previous versions the volume covered the labels. Is ti possible to get that feature back?

The solution doesn’t seem to be too useful for our purposes.

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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:** [October 3, 2022, 3:18pm UTC](https://discourse.slicer.org/t/control-point-labels-show-through-3d-volume-in-volume-rendering/25517/4 "2022-10-03T15:18:02Z")

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> [@Pheasant](#):
>
> In the previous versions the volume covered the labels. Is ti possible to get that feature back?

I don’t know, that’s up to the developers and how strongly this is needed by user base. I occasionally needed to do same need, but so far solution worked for me. I also find it a bit strange that the glyph can be occluded by the volume but not the accompanying label.

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**Author:** ![rbumm](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/rbumm/32/9404_2.png) [@rbumm](https://discourse.slicer.org/u/rbumm)\
**Post date:** [October 3, 2022, 4:00pm UTC](https://discourse.slicer.org/t/control-point-labels-show-through-3d-volume-in-volume-rendering/25517/5 "2022-10-03T16:00:53Z")

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Thank you for the report. The markup labels should definitely be occluded by the volume in the 3D view and I can reproduce they are not in Slicer 5.0.3 and 5.1. This looks like an issue and probably should be reported unless we oversee something here.

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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:** [October 3, 2022, 5:51pm UTC](https://discourse.slicer.org/t/control-point-labels-show-through-3d-volume-in-volume-rendering/25517/6 "2022-10-03T17:51:13Z")

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I recall vaguely a discussion with @lassoan and was under the impression that choice was by design (keeping the labels on all times).

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**Author:** ![Pheasant](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pheasant/32/15560_2.png) [@Pheasant](https://discourse.slicer.org/u/Pheasant)\
**Post date:** [October 4, 2022, 5:56am UTC](https://discourse.slicer.org/t/control-point-labels-show-through-3d-volume-in-volume-rendering/25517/7 "2022-10-04T05:56:13Z")

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That would be a weird design choice but hopefully the choice can be implemented. Thanks for the possible work around though, it can work in an emergency.

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**Author:** ![rbumm](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/rbumm/32/9404_2.png) [@rbumm](https://discourse.slicer.org/u/rbumm)\
**Post date:** [October 4, 2022, 3:56pm UTC](https://discourse.slicer.org/t/control-point-labels-show-through-3d-volume-in-volume-rendering/25517/8 "2022-10-04T15:56:59Z")

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> [@rbumm](#):
>
> The markup labels should definitely be occluded by the volume

Sorry, I need to correct my post: The markup labels are occluded by _segmentations_ in 3D Slicer and not by volume renderings.

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**Author:** ![Pheasant](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pheasant/32/15560_2.png) [@Pheasant](https://discourse.slicer.org/u/Pheasant)\
**Post date:** [November 1, 2022, 7:43am UTC](https://discourse.slicer.org/t/control-point-labels-show-through-3d-volume-in-volume-rendering/25517/9 "2022-11-01T07:43:36Z")

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So will it be fixed then? In previous versions the labels were occluded by volume renderings and I am not sure why this change occured if it is intentional.

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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:** [November 4, 2022, 11:56am UTC](https://discourse.slicer.org/t/control-point-labels-show-through-3d-volume-in-volume-rendering/25517/10 "2022-11-04T11:56:20Z")

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> [@Pheasant](#):
>
> In the previous versions the volume covered the labels

Can you please tell us in which version you refer to? (The latest in that the volume covered the labels)

I imagine it was a long time ago, when 3D text actors were used to show labels, however, they had serious issues and then 2D text actors were introduced instead that are not occluded by 3D objects like volume rendering.

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<div class="post-metadata">

**Author:** ![Pheasant](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pheasant/32/15560_2.png) [@Pheasant](https://discourse.slicer.org/u/Pheasant)\
**Post date:** [November 4, 2022, 12:05pm UTC](https://discourse.slicer.org/t/control-point-labels-show-through-3d-volume-in-volume-rendering/25517/11 "2022-11-04T12:05:39Z")

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The latest I can find where it works is 4.10 it would seem.

What sort of issues were there regarding them? What would be the difference between the text and the points as those are properly occluded?

Would it be possible to link a hidden markup point to the text and hide the text if it the point is occluded or are the two objects completely different things?