VTK.js . I render a volume with vtkImageCroppingWidget (nice clear box). When I add a vtkImplicitPlaneWidget to show a cutting plane, the plane’s face visibly darkens the volume (gray pixels) instead of being fully see-through. I only want the outline/handles, with no filled face and no depth/write that occludes the volume.
What’s the correct way to configure the ImplicitPlaneWidget (or its representations) so it renders like the cropping widget (clear, non-occluding)?