Adjusting "Shift" Volume Rendering Display using Python

Hi,

I am trying to visualize a volume using Python and volume rendering.
When I render the volume, it is rather dark. I know I can solve this by moving the “Shift” bar under Display in Volume Rendering. Now I tried doing this by using Python, and I used the following code:

volRenLogic = slicer.modules.volumerendering.logic()
displayNode = volRenLogic.CreateDefaultVolumeRenderingNodes(node)
layoutManager = slicer.app.layoutManager()
threeDWidget = layoutManager.threeDWidget(0)
threeDView = threeDWidget.threeDView()
threeDView.resetFocalPoint()

volRenWidget = slicer.modules.volumerendering.widgetRepresentation()
volumePropertyNode = displayNode.GetVolumePropertyNode()

volumePropertyNodeWidget = slicer.util.findChild(volRenWidget, ‘VolumePropertyNodeWidget’)
volumePropertyNodeWidget.setMRMLVolumePropertyNode(volumePropertyNode)
volumePropertyNodeWidget.moveAllPoints(x, 0, false)

It does visualize the volume (which is a CT scan), but when I try to apply the shift change, no visible changes are applied to the visualized volume. It does not matter what i fill in at x, but nothing seems to work, I do not get any Error messages either, it just straight up does not show the changes I made. I have tried searching these forums for a suitable answer, but i did not find anything that would completely solve this issue, and I hope anyone can help me out on this.