Customizing Nuke with Gizmos - Nuke 101: Professional Compositing and Visual Effects - page 521

10. Change the Name and Label to SafeAreas . Click OK.
11. Click Done.
You now have a new type of Knob that you created (well, sort of—you actually
copied it): a pull-down menu called operation. Changing it changes how the Safe
Areas are composited over the image ( FIGURE 12.38 ) .
Figure 12.38. Your new Knob is a pull-down menu.
Now to create the two Knobs to replace the Knobs in NoOp1. Let's run through
this:
12. Right-click (Ctrl-click) an empty spot in Group1's Properties panel and choose
Manage User Knobs from the contextual menu.
13. Click the Add button and from the pull-down menu click Width/Height Knob.
14. Name this actionSafe andlabel it actionSafe .Inthe Tooltip field, enter Controls
percentage of Safe Area ( FIGURE 12.39 ) . Click OK.
Figure 12.39. Recreating the Action Safe area Knob.