Yes, those were outputs I got after careful “shift” slider movements in the Volume Rendering module (3D Slicer 5). The slider is very sensitive.
Volume renderings do not create models or segmentations that could be transformed into STL files.
Please see here for an explanation.
If your end goal is to have an STL file of the airways, I would really recommend you do a proper airway segmentation with your data. Segmentation tools are available ins Slicer (see “Segment Editor”), and semiautomatic AW segmentation can be done with the Lung CT Segmenter, part of the Lung CT Analyzer extension.
If that is not your end goal, pls describe it.