Masking in Toji Motion: Hide and Reveal Layers Cleanly

What a Mask Actually Does

A mask is a shape drawn over a layer that decides where the layer shows and where it vanishes. Inside the shape, the layer lives; outside it, whatever sits beneath comes through. In the Toji Motion editor nearly every polished reveal, wipe and text-behind-object effect is a mask doing quiet work.

Think of it as cutting a window rather than painting a picture. The layer itself never changes; you are only choosing the part of it the audience is allowed to see.

Your First Mask Reveal

Start with the classic: a title revealed as if a curtain lifts. Put a text layer over a background, draw a rectangle mask across the whole text, then shrink the mask to nothing at the layer's first frame. One second later, open the mask to full width. Played back, the title wipes into existence.

Draw masks at the frame where they must fit best, usually the end state, and work backwards. A mask drawn loosely at the wrong moment spends the whole animation apologising for itself.

Feather and Edges

A hard mask edge is a confession. Real light and real focus fall off gradually, so feather the edge until the boundary stops announcing itself, then judge at playback speed rather than frozen. Still frames make liars of us all: an edge that looks rough paused may be invisible in motion, and the reverse is just as true.

Layer order decides the rest. How masks interact with the layers beneath them leans on the same logic as our blending modes guide: what sits below a masked layer is part of the effect, not an accident.

Masking With Keyframes

The mask becomes an instrument when its shape and position take keyframes of their own: a window that follows a moving subject, a reveal that tracks a hand, a wipe with an angle. The method is the one from our keyframes guide, with the mask's points joining position and scale as things that can promise two states and glide between them.

Keep the point count low. Every extra point is a promise you must keep at every keyframe, and simple masks animated bravely beat complex masks animated timidly.

When you need the app itself, the download page on this site is the place to get it.