NkView is an open source, python Qt tool for viewing .nk files.
At the moment the tool supports PySide2 and PySide6.
Once you have installed nkview, you can launch from the command line:
nkview
You can also specify a file to open.
nkview -o test_scenes/nested_group.nk
The Outliner shows a hierarchical list of all objects in the scene in outline form.
Press the Ctrl key while scrolling to zoom in / out in the outliner.

The Node Graph presents a schematic of the nk dependency graph, displaying nodes and their connections
- To pan with the mouse, press the middle mouse button and drag the mouse pointer over the graph.
- To zoom use the scroll wheel to zoom in / out.

The Node Graph allows you to explore nodes inside gizmos and groups. To enter a group or gizmo doubleclick on the node you want to expand in the Node Graph or Outliner.

nkview -o path/to/file.nk


