# Threshold Error on segmentation and does not show 3D reconstruction

**URL:** <https://discourse.slicer.org/t/threshold-error-on-segmentation-and-does-not-show-3d-reconstruction/21999>\
**Category:** Support\
**Created:** [February 16, 2022, 5:30pm UTC](https://discourse.slicer.org/t/threshold-error-on-segmentation-and-does-not-show-3d-reconstruction/21999 "2022-02-16T17:30:53Z")\
**Posts on this page:** 1\
**Showing post:** 6

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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:** [February 24, 2022, 10:52pm UTC](https://discourse.slicer.org/t/threshold-error-on-segmentation-and-does-not-show-3d-reconstruction/21999/6 "2022-02-24T22:52:04Z")

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You can use the method I described here to correctly scale your existing segmentations and your volumes.

> [@Ruler in (orthographic) 3D view](https://discourse.slicer.org/t/ruler-in-orthographic-3d-view/4656/23):
>
> As you are observing, it is important to check that the imported image stack has the correct image spacing as the first step of your workflow. Since everything else (segmentations → models → measurements) are all dependent on this piece of information. This is especially true if you importing these images from 2D formats like PNG/TIFF etc which doesn’t preserve this information. You don’t have to redo the segmentation but it will take you a few steps to get them in correct alignment. This is wh…

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_[View the full topic](https://discourse.slicer.org/t/threshold-error-on-segmentation-and-does-not-show-3d-reconstruction/21999)._