# Exported STL files dont match view in Slicer

**URL:** <https://discourse.slicer.org/t/exported-stl-files-dont-match-view-in-slicer/16441>\
**Category:** Support\
**Created:** [March 8, 2021, 11:19pm UTC](https://discourse.slicer.org/t/exported-stl-files-dont-match-view-in-slicer/16441 "2021-03-08T23:19:57Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![benv](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/benv/32/10201_2.png) [@benv](https://discourse.slicer.org/u/benv)\
**Post date:** [March 8, 2021, 11:19pm UTC](https://discourse.slicer.org/t/exported-stl-files-dont-match-view-in-slicer/16441/1 "2021-03-08T23:19:57Z")

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I’m trying to export a segmentation to an STL mesh. I’m able to export it and read it in successfully, but the mesh I get out doesn’t seem to match up to what I see in Slicer. In the attached image, you can see point 6 and 7 are well within the yellow segmentation (right), but in the exported STL file, 7 ends up outside the mesh (left). Is there something I can do to export the mesh with higher fidelity?

As an alternative, I was considering exporting 2D slices of the segmentations. Is there a way to do this?

I’m using slicer 4.10.2 on a MBP, and Matlab 2020a.

Thanks!  
-Ben

 ![Screen Shot 2021-03-08 at 10.47.16 AM](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/8/e/8e9f2e2c55130a943232041752f9f50bd50e8fd8.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:** [March 8, 2021, 11:24pm UTC](https://discourse.slicer.org/t/exported-stl-files-dont-match-view-in-slicer/16441/2 "2021-03-08T23:24:45Z")

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Slicer now reads all files in LPS coordinate system. Before Slicer-4.11, it expected STL files to be in RAS coordinate system by default. See more information about how to avoid RAS/LPS mismatch in the [migration guide](https://www.slicer.org/wiki/Documentation/Nightly/Developers/Tutorials/MigrationGuide/Slicer#Slicer_5.0:_Models_are_saved_in_LPS_coordinate_system_by_default).

If there is no LPS/RAS issue but slight position and/or orientation differences then most likely that other software does not properly take into account image origin, spacing, or axis directions of the input volume.