# Volume Rendering ROI SetAndObserveROINodeID problem

**URL:** <https://discourse.slicer.org/t/volume-rendering-roi-setandobserveroinodeid-problem/9608>\
**Category:** Support\
**Created:** [December 24, 2019, 3:58pm UTC](https://discourse.slicer.org/t/volume-rendering-roi-setandobserveroinodeid-problem/9608 "2019-12-24T15:58:21Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![apparrilla](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/apparrilla/32/9230_2.png) [@apparrilla](https://discourse.slicer.org/u/apparrilla)\
**Post date:** [December 24, 2019, 3:58pm UTC](https://discourse.slicer.org/t/volume-rendering-roi-setandobserveroinodeid-problem/9608/1 "2019-12-24T15:58:21Z")

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Merry Christmas everyone.

I´ve made a function to init VR with a previously made ROI.  
I want to have full interaction with Slicer VR module for advance use if i need it.

It looks like:

> def InitVRDisplayNode(self):  
> volumeRenderingWidgetRep = slicer.modules.volumerendering.widgetRepresentation()  
> volumeRenderingWidgetRep.setMRMLVolumeNode(InputVolumeNode())  
> bonepreset = slicer.modules.volumerendering.logic().GetPresetByName(‘CT-AAA’)  
> volumeRenderingNode = slicer.mrmlScene.GetFirstNodeByName(‘VolumeRendering’)  
> volumeRenderingNode.GetVolumePropertyNode().Copy(bonepreset)  
> volumeRenderingNode.SetCroppingEnabled(1)  
> volumeRenderingNode.SetAndObserveROINodeID(RoiNode.GetID())  
> volumeRenderingNode.SetVisibility(1)

At this point, VR is visible but ROI changes do not crop VR and Slicer VR module do not interact with visible VR image.

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<div class="post-metadata">

**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:** [January 15, 2020, 2:29am UTC](https://discourse.slicer.org/t/volume-rendering-roi-setandobserveroinodeid-problem/9608/2 "2020-01-15T02:29:09Z")

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Does everything work well if you create the ROI node on the GUI?  
Try with both latest stable and latest preview release.