This patch adds the ability to mute individual wires in the node editor.
This is invoked like the cut links operator but with a new shortcut.
Mute = Ctrl + Alt
Cut = Ctrl
Dragging over wires will toggle the mute state for that wire.
The muted wires are drawn in red with a bar across the center.
Red is used in the nodes context to indicate invalid links, muted links and internal links.
When a wire is muted it exposes the original node buttons which are normally hidden when a wire is connected.
Downstream and upstream links connected using reroute nodes are also muted.
Outside scope of patch:
- Add support for pynodes e.g. Animation Nodes
- Requires minor change to check for muted links using the `is_muted` link property or the `is_linked` socket property.
Maniphest Tasks: T52659
Differential Revision: https://developer.blender.org/D2807
