Animation
Masks and guides
Two special kinds of layer change how other layers are drawn: a mask shows the layers beneath it only through its shapes, and a guide holds artwork that helps you work but never appears in the finished animation.
Masks
A mask layer acts like a window. Wherever it has artwork, the layers masked by it show through; everywhere else, they are hidden.
Make a mask
- Put the artwork to be revealed on a layer.
- Add a layer directly above it and draw the window shape on it. Its color doesn't matter.
- Right-click the upper layer and choose Mask. The layer below becomes masked by it, and both are locked so you see the result.
To mask more layers with the same mask, drag them into place directly under the mask layer, or set their type to Masked in Layer Properties.
How masks behave
- Only fills count. Strokes on a mask layer are ignored.
- Transparency in the mask is ignored: a half-transparent fill masks just like a solid one, with a hard edge.
- Masks can be animated. Tween or draw the mask frame by frame for wipes, spotlights and reveals.
- On the stage, a mask masks only while its layer is locked. Unlock it to see and edit the mask's own artwork, with the layers under it shown whole; lock it again to see the result. Exports always mask.
Soft, grown and inverted masks
Right-click a mask layer and choose Mask Edge... to change how it masks: Feather fades its edge softly over that many pixels, Expand grows it (or shrinks it, below 0) by that many pixels, and Invert shows what is outside the mask instead of inside, for a hole cut in a picture or a vignette. The mask's art keeps its shape; the edge is worked out as it draws, on the stage and in every export. Other apps that open the FLA draw the mask hard-edged and not inverted.
The feather can differ along a mask. Select objects on the mask layer (unlock it first) and open Mask Edge...: Selected objects gives them a feather of their own in place of the layer's, so one mask can be soft round a spotlight and hard along a window frame. Each keyframe keeps its objects' feathers, and a tween blends between them, so an edge can soften or sharpen as the mask moves. Set it back to The layer's to follow the layer again.
Several masks on a layer
A masked layer can be masked by other mask layers of its timeline as well as its own. Right-click it and choose Also Masked By, then a mask layer and how it combines:
- Add shows the layer where either mask is.
- Subtract cuts the layer out where that mask is: a hole through a window.
- Intersect shows the layer only where both masks are.
The order you add them in does not matter: Add masks widen what shows, then Intersect masks limit it, then Subtract masks cut it. Each mask keeps its own edge, feathered or inverted. A mask layer used only this way needs no layers of its own under it; renaming it keeps the layers that use it pointing at it. carries several masks over with movie clips: the layer's art in a clip under its own mask, masked again by each Intersect mask and erased by the Subtract masks inside it, and a layer for each Add mask; their edges are hard there.
Layer modes
A layer's right-click menu has Layer Mode, for working with everything drawn under the layer rather than a single layer below:
- Stencil shows what is under the layer only where the layer has art; the layer's own art is not drawn. A shape on top of a whole scene becomes a window onto it.
- Silhouette is the reverse: it cuts what is under out where the layer has art.
- Preserve Transparency draws the layer only where something is already drawn under it: a texture, a gradient or a light sweep that stays inside the art below.
Guide layers
Right-click a layer and choose Guide to turn it into a guide layer. Use guide layers for sketches, layout drawings, reference images and notes. They are drawn while you work but left out of every export.
Imported reference video goes onto a locked guide layer automatically, so it is there to animate over but never ends up in your render.
Motion guides
A motion guide moves an object along a path you draw.
- Make a classic tween of an instance.
- Add a guide layer above it and draw the path with the Pen, Pencil or Line tool.
- Drag the tweened layer under the guide layer so it becomes guided, or set its type to Guided in Layer Properties.
- At the first and last keyframes, place the instance on the path's ends. With Snap on in the Frame tab, it snaps onto the path.
The instance now follows the stroke between the keyframes. Check Orient to path in the Frame tab's Tweening section, on the tween's first keyframe, and the instance also turns as the path turns.