The Spline Mask Editor Window

We can open the Spline Mask Editor Window of a Spline Mask node by click on its Edit Spline button, in which we can do the following operations:

Operation	How
Add a point to the active spline	Shift + Right Click.
Open a pop-up menu to execute an action based on the clicked position	Right Click.
Move the position of a control point	Click the control point and drag it. Pressing Ctrl while dragging will snap the control point to the nearest grid point if the grid is visible.
Change the in or out direction of a control point	Click the control point and change its tangent by dragging one of its surrounding points.
Change the tangent mode of a control point	Right Click on the control point and change its Tangent Mode property.
Change the active spline	Click on one of the control points or the edges of the spline.
Add a control point to the current selection	Press Shift while clicking on the control point.
Delete selected control points	Press Del.

Tangent Mode

We can set the tangent mode of a control point with one of the following values:

Tangent Modes	Description
Broken Free	Drag the tangent handle to freely set the tangents.
Broken Linear	The tangent points towards the neighboring point. To make a linear curve segment, set the tangents at both ends to be Broken Linear.
Free Smooth	Drag the tangent handles to freely set the tangents. They are locked to be co-linear to ensure smoothness.

Other Properties

The Spline Mask Editor window also has the following configurable properties to make editing easier.

Properties	Description
Grid Size	Sets the grid size.
Show Grid	Shows or hides the grid.
Spline Col	The color of spline curves.
Point Col	The color of control points.
Tangent Col	The color of the end points of tangent lines.