Editing of mask splines happens in a way similar to editing bezier curves or paths in GIMP or other curve editors: control points are added to define the spline itself, and handles of different types are used to create smooth bends. This makes it possible to define a mask with few points to easily follow an object in footage.
- Ctrl + LMB is used to place new control points and define handle orientations (click to place control point, click followed with slide to place new control point and set smoothness for it).
- Alt + C: to close the mask by joining the last control point to the first.
- Existing control points can be translated, scaled and rotated with the usual G, S, R shortcuts.
- X or Delete removes control points.
The usual selection and hide/reveal tools are available:
- A: toggle select all
- B, C: border and circle Select
- Ctrl + L select linked from selection, L: select linked with mouse
- Ctrl + Alt + LMB : lasso select
- H hide selected, ⇧ Shift + H hide unselected, Alt + H reveal
- Alt + C: cycle toggle spline, to create a close curve or open it again
- V: set handle type for selected spline points
- Ctrl + N: make normals (handle directions) consistent
- Switch Direction handle directions in/out.
It’s possible to control feather of mask, including a way to define non-linear feather. Linear feather is controlled by a slider, non-linear feather is controlled in the same curve-based way to define feather falloff.
- ⇧ Shift + LMB is used to define a feathering outline curve. To create an initial feather, sliding from a spline control point outside or inside will create and position feather points. After this ⇧ Shift + LMB will insert new feather point and mouse sliding can be used to move them around.
- Alt + S will scale the feather size.