# How to draw arrows on the reslicer using vtk?

**URL:** https://discourse.vtk.org/t/how-to-draw-arrows-on-the-reslicer-using-vtk/8719
**Category:** Support
**Tags:** jobs, proposal
**Created:** [June 14, 2022, 7:36am UTC](https://discourse.vtk.org/t/how-to-draw-arrows-on-the-reslicer-using-vtk/8719 "2022-06-14T07:36:38Z")
**Posts on this page:** 3
**Page:** 1

<div class="post-metadata">

### Author: ![wulicheng](https://discourse.vtk.org/user_avatar/discourse.vtk.org/wulicheng/32/1990_2.png) [@wulicheng](https://discourse.vtk.org/u/wulicheng)
#### Post date: [June 14, 2022, 7:36am UTC](https://discourse.vtk.org/t/how-to-draw-arrows-on-the-reslicer-using-vtk/8719/1 "2022-06-14T07:36:38Z")

</div>

How to draw an arrow like the 3D slicer?

---

<div class="post-metadata">

### Author: ![mau\_igna\_06](https://discourse.vtk.org/user_avatar/discourse.vtk.org/mau_igna_06/32/8064_2.png) [@mau\_igna\_06](https://discourse.vtk.org/u/mau_igna_06)
#### Post date: [June 14, 2022, 11:17am UTC](https://discourse.vtk.org/t/how-to-draw-arrows-on-the-reslicer-using-vtk/8719/2 "2022-06-14T11:17:02Z")

</div>

Something like you would need to use an arrowSource and then a GlyphSource oriented by the eigenvectors filter. You can check out how it’s done in Slicer:  
I guess this is what you’d like to see:

> <https://github.com/Slicer/Slicer/blob/15671043411809e62742101b9b3fd843fd4739c9/Modules/Loadable/Markups/VTKWidgets/vtkSlicerMarkupsWidgetRepresentation3D.cxx>

---

<div class="post-metadata">

### Author: ![wulicheng](https://discourse.vtk.org/user_avatar/discourse.vtk.org/wulicheng/32/1990_2.png) [@wulicheng](https://discourse.vtk.org/u/wulicheng)
#### Post date: [June 15, 2022, 1:22am UTC](https://discourse.vtk.org/t/how-to-draw-arrows-on-the-reslicer-using-vtk/8719/3 "2022-06-15T01:22:14Z")

</div>

thanks! I have not read code of 3D slicer. So thanks for your suggestion!