Alpha Shapes (Mask)

This filter 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]

For a more detailed description of the Alpha Shapes effect refer to the Alpha Shapes section of the documentation.