Alpha Shapes (Mask)¶

Description

This effect essentially works like the Alpha Shapes effect but takes a snapshot of the frame before it draws simple shapes into the alpha channel. Use it together with the Mask Apply effect that uses a transition to composite the current frame’s image over the snapshot. The typical use case is to add effects in the following sequence:

Alpha Shapes Mask (this effect) –> zero or more effects (e.g. Blur, Cartoon) –> Mask Apply [–> more effects if needed]

Parameters

Parameter	Value	Description
Shape	Selection	Controls the shape of the area of opacity that the effect will create.
Operation	Selection	Defines what is to happen when you have more than one alpha effect on the clip
Position X / Y	Integer	Defines the position of the shape on the screen. The range of values is from 0 to 1000 where 500 defines the middle of the screen.
Size X / Y	Integer	Defines the size of the shape. The range of values is from 0 to 1000 where 500 defines 100%,
Tilt	Integer	Controls the angle the shape appears on the screen. The units are in 1000ths of a full rotation. For example, a value of 250 is one quarter of a circle turn and 500 is a 180-degree turn. That means, 1000 tilt units = 360 degrees.
Transition width	Integer	Defines the width of a border on the shape where the transparency grades from the inside to the outside of the shape. Can be used for feathering or creating a frame.
Min	Integer
Max	Integer

The following selection items are available:

Shape

Rectangle	Draws a rectangle
Ellipse	Draws an ellipse/circle
Triangle	Draws a triangle
Diamond	Draws a diamond

Operation

Write On Clear	Existing alpha mask is overwritten
Max	Take the maximum between the existing alpha mask and the mask generated by this filter
Min	Take the minimum between existing alpha mask and mask generated by this filter
Add	Add the existing alpha mask and the mask generated by this filter
Subtract	Subtract from the existing alpha mask the mask generated by this filter

Notes