# About CellPicker when markup by line

**URL:** <https://discourse.slicer.org/t/about-cellpicker-when-markup-by-line/29100>\
**Category:** Support\
**Tags:** markups\
**Created:** [April 25, 2023, 2:14am UTC](https://discourse.slicer.org/t/about-cellpicker-when-markup-by-line/29100 "2023-04-25T02:14:52Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![dbtruong](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/dbtruong/32/65581_2.png) [@dbtruong](https://discourse.slicer.org/u/dbtruong)\
**Post date:** [April 25, 2023, 2:14am UTC](https://discourse.slicer.org/t/about-cellpicker-when-markup-by-line/29100/1 "2023-04-25T02:14:52Z")

</div>

Hello everyone,  
vtkCellPicker will got a point in the world coordinates when click on surface. How to find the points isn’t on surface?

---

<div class="post-metadata">

**Author:** ![dbtruong](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/dbtruong/32/65581_2.png) [@dbtruong](https://discourse.slicer.org/u/dbtruong)\
**Post date:** [April 25, 2023, 4:59am UTC](https://discourse.slicer.org/t/about-cellpicker-when-markup-by-line/29100/2 "2023-04-25T04:59:28Z")

</div>

![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/2/e/2e2626d9018c297ede166f013da320a90616dcbd.png)