# How to get the central point of 3 slice panel

**URL:** <https://discourse.slicer.org/t/how-to-get-the-central-point-of-3-slice-panel/29853>\
**Category:** Development\
**Created:** [June 6, 2023, 2:22am UTC](https://discourse.slicer.org/t/how-to-get-the-central-point-of-3-slice-panel/29853 "2023-06-06T02:22:51Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![jay1987](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/jay1987/32/16183_2.png) [@jay1987](https://discourse.slicer.org/u/jay1987)\
**Post date:** [June 6, 2023, 2:22am UTC](https://discourse.slicer.org/t/how-to-get-the-central-point-of-3-slice-panel/29853/1 "2023-06-06T02:22:51Z")

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![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/7/f/7fe77a3fe28b9f6a1a12ce92cc4d4530f190203b.png)  
the requirement is to get the central point’s layer number of a volume node , i can get the 3d focus point , but i don’t known how to get the 3 sliceview focus global position like the F-1 markups point in the picture above

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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 16, 2023, 4:45pm UTC](https://discourse.slicer.org/t/how-to-get-the-central-point-of-3-slice-panel/29853/2 "2023-06-16T16:45:40Z")

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If you use layout with more or less than 3 slices or if some slices are nearly parallel then an intersection point cannot be determined. Therefore, there is no Slicer core API for getting the 3D coordinates of the intersection point.

Instead, of getting a point coordinate, I would recommend to use markup points (you can activate point placement and ask the user to click on an image or in a 3D view) or use crosshair (you can set the crosshair position by holding down the Shift key while moving the mouse in a view).

If you really must use the slice intersections, then you can of course compute it for yourself, as it is done for example in SlicerHeart extension:

> <https://github.com/SlicerHeart/SlicerHeart/blob/52eeb23576c7eda14dbe3e602667f4c5b68c4475/ValveView/ValveView.py#L213-L273>

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**Author:** ![jay1987](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/jay1987/32/16183_2.png) [@jay1987](https://discourse.slicer.org/u/jay1987)\
**Post date:** [June 17, 2023, 4:21am UTC](https://discourse.slicer.org/t/how-to-get-the-central-point-of-3-slice-panel/29853/3 "2023-06-17T04:21:01Z")

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thank you lassoan , it’s really help