# BoxWidget in a vtkMultiVolume renderer with more than one volume

**URL:** https://discourse.vtk.org/t/boxwidget-in-a-vtkmultivolume-renderer-with-more-than-one-volume/5386
**Category:** Development
**Created:** [March 15, 2021, 1:16pm UTC](https://discourse.vtk.org/t/boxwidget-in-a-vtkmultivolume-renderer-with-more-than-one-volume/5386 "2021-03-15T13:16:24Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![MissMac](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/m/c57346/32.png) [@MissMac](https://discourse.vtk.org/u/MissMac)
#### Post date: [March 15, 2021, 1:16pm UTC](https://discourse.vtk.org/t/boxwidget-in-a-vtkmultivolume-renderer-with-more-than-one-volume/5386/1 "2021-03-15T13:16:24Z")

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Hello,

I render three volumes using the vtkMultiVolume renderer.

Know, I need to apply a BoxWidgets to clip/crop the volumes.  
However, when I apply the BoxWidget, the Box is shown, but the Volume stays as it is.  
When I render only one volume, it works as expected.

Does anyone know if VTK 9.x supports BoxWidgets in vtkMultiVolume renderer?

Thanks you very much.

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### Author: ![sankhesh](https://discourse.vtk.org/user_avatar/discourse.vtk.org/sankhesh/32/73_2.png) [@sankhesh](https://discourse.vtk.org/u/sankhesh)
#### Post date: [March 15, 2021, 2:49pm UTC](https://discourse.vtk.org/t/boxwidget-in-a-vtkmultivolume-renderer-with-more-than-one-volume/5386/2 "2021-03-15T14:49:14Z")

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How are you applying the box to the volume mapper? In the case of `vtkMultiVolume` you’d have to apply the clip planes to each individual mapper.

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### Author: ![MissMac](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/m/c57346/32.png) [@MissMac](https://discourse.vtk.org/u/MissMac)
#### Post date: [March 15, 2021, 5:14pm UTC](https://discourse.vtk.org/t/boxwidget-in-a-vtkmultivolume-renderer-with-more-than-one-volume/5386/3 "2021-03-15T17:14:46Z")

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Thank you for your answer.

As mapper I use the vtkGPUVolumeRayCastMapper.

I am adding the volume (vtkImageData) as input to the BoxWidget and apply the vtkGPUVolumeRayCastMapper to the Observer: