Complex masks overview

With the Draw Mask effect, you can draw complex masks using splines. Splines are vector-based curves that allow for complex, customized shapes. There are two spline drawing methods:

  • Bezier splines: Bezier splines are good for drawing shapes for illustration. The controls used to manipulate Bezier splines are similar to those found in many other drawing and compositing applications. Bezier controls lend themselves to the creation of precise, detailed shapes. Tangent handles adjust the curvature of the shape on either side of the control point, defining the surface of the shape.

    Viewer showing Bezier control point and its tangent handles
  • B-Splines: You can also use B-Splines to draw shapes. Unlike Bezier splines, B-Splines are manipulated using only points—there are no tangent handles. Furthermore, the points themselves do not lie on the surface of the shape. Instead, each B-Spline control point is offset from the shape’s surface, magnetically pulling that section of the shape toward itself to create a curve. By combining the influence of multiple B-Spline points, you can create different curves. B-Splines are extremely smooth—by default, there are no sharp angles in B-Spline shapes, although you can create sharper curves, if necessary.

    Viewer showing B-Spline control point

    Because B-Spline controls are so simple, they’re easy to animate and manipulate. The tools you use for a specific task are largely a matter of personal preference.

You can also draw masks with linear control points, which are connected by straight lines. Linear control points are also known as corner points. You can convert control points between linear (corner) points and smooth (Bezier) points at any time.

Viewer showing linear corner point

Note: By default, the Draw Mask is set to draw with Bezier shapes. If you prefer to draw your mask with linear or B-Spline shapes, you can adjust this setting in the Video inspector before you get started.