# Point coordinates in model imported into the 3D Slicer differ from the coordinates in the file

**URL:** https://discourse.slicer.org/t/point-coordinates-in-model-imported-into-the-3d-slicer-differ-from-the-coordinates-in-the-file/28305
**Category:** Support
**Tags:** transforms
**Created:** [March 11, 2023, 5:32am UTC](https://discourse.slicer.org/t/point-coordinates-in-model-imported-into-the-3d-slicer-differ-from-the-coordinates-in-the-file/28305 "2023-03-11T05:32:20Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![BARNEY](https://avatars.discourse-cdn.com/v4/letter/b/48db29/32.png) [@BARNEY](https://discourse.slicer.org/u/BARNEY)
#### Post date: [March 11, 2023, 5:32am UTC](https://discourse.slicer.org/t/point-coordinates-in-model-imported-into-the-3d-slicer-differ-from-the-coordinates-in-the-file/28305/1 "2023-03-11T05:32:20Z")

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Hi, all!  
I was wondering why the position point of the 3D slicer I imported directly is different from the actual one.

 ![2023-03-11 13.29.02](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/8/d/8dd19f2f75434fc6511ba0fd56c294139bbbafad.png)  
 ![截屏2023-03-11 13.28.46](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/1/d/1d78d1751d2d3af3ba8cf5900cc3b327cda03a3e.png)  
 ![截屏2023-03-11 13.29.35](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/c/3/c3326d3c40512f51069f4022fa5b1407b194eb4c.png)

As shown in the figure, the red dot represents a model I imported into slicer (vtk format), which is represented by 6 dots, respectively 0.00 0.00 0.00, -0.04 0.33 1.10, -0.15 1.22 1.82,  
-0.30 2.35 1.92, -0.42 3.35 1.37, -0.49 3.87 0.35, the red cubes in the pictures.  
But I visualized the points by entering the X, Y, Z coordinate values, and found that there was a difference between them, specifically the X and Y values turned negative.  
So? Is there something wrong in the transform hierarchy？  
Any advice will be great! Thank you！

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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 11, 2023, 6:30am UTC](https://discourse.slicer.org/t/point-coordinates-in-model-imported-into-the-3d-slicer-differ-from-the-coordinates-in-the-file/28305/2 "2023-03-11T06:30:11Z")

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Almost all medical image computing software standardized on using LPS coordinate system in files. Slicer follows this convention. If coordinate values in your model file are in RAS coordinate system and you don’t want to change that then you can indicate this in the file header. See more information at these links:

- [Documentation/Nightly/Developers/Tutorials/MigrationGuide/Slicer - Slicer Wiki](https://www.slicer.org/wiki/Documentation/Nightly/Developers/Tutorials/MigrationGuide/Slicer#Slicer_5.0:_Models_are_saved_in_LPS_coordinate_system_by_default)
- [Data Loading and Saving — 3D Slicer documentation](https://slicer.readthedocs.io/en/latest/user_guide/data_loading_and_saving.html#models)

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### Author: ![BARNEY](https://avatars.discourse-cdn.com/v4/letter/b/48db29/32.png) [@BARNEY](https://discourse.slicer.org/u/BARNEY)
#### Post date: [March 12, 2023, 9:02am UTC](https://discourse.slicer.org/t/point-coordinates-in-model-imported-into-the-3d-slicer-differ-from-the-coordinates-in-the-file/28305/3 "2023-03-12T09:02:29Z")

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That is very helpful! Thank you very much!