Motion design, defined
40 terms you will meet in any motion tool, each defined once and then shown where it lives in Premation.
- Adjustment layer
- A layer with no content of its own whose effects apply to everything rendered beneath it in the stack.
- Anchor point
- The origin a layer rotates and scales around. Moving it changes what a rotation pivots on without moving the layer itself.
- Blend mode
- How a layer's pixels combine with what is already drawn beneath it: multiply darkens, screen lightens, difference inverts where they overlap.
- Bone
- One rigid segment of a skeleton. Bones chain into a hierarchy; rotating a parent rotates every child with it.
- Composition
- A canvas with a size, frame rate, duration and background, plus the stack of layers drawn on it. The unit you animate in and export from.
- Depth of field
- The range of distances that appear sharp. Everything nearer or farther than the focus distance blurs, more with a wider aperture.
- Easing
- The rate at which a value travels between two keyframes. Linear is constant speed; an ease slows into or out of a keyframe, which is what makes motion read as physical.
- Effect stack
- The ordered list of effects applied to one layer. Order matters: a blur before a glow and a glow before a blur are different pictures.
- Expression
- Code that computes a property's value every frame instead of reading it from keyframes. Wiggle, loops and links between properties are the classic uses.
- Frame blending
- Synthesising in-between frames when footage is slowed down or its frame rate does not match the composition, instead of duplicating or dropping frames.
- Graph editor
- A view of animation as curves: value over time, or speed over time. Dragging the handles reshapes how a property moves between keyframes.
- Hold keyframe
- A keyframe with no interpolation after it: the value stays fixed until the next keyframe, then jumps. Used for cuts, blinks and stepped motion.
- IK and FK
- Two ways to pose a chain of bones. Forward kinematics rotates each bone and the children follow. Inverse kinematics moves a target and the chain solves to reach it.
- Keyframe
- A recorded value at a point in time. Two keyframes and an interpolation between them are the whole basis of animation.
- Layer
- One element in a composition: a shape, text, image, video, audio clip, camera, light, null or nested composition, with its own transform and time span.
- Layer style
- A treatment that follows a layer's shape rather than its pixels: drop shadow, inner glow, bevel, satin, stroke. Photoshop's idea, borrowed by every motion tool.
- Linear blend skinning
- How a mesh follows a skeleton: every vertex takes a weighted mix of the transforms of the bones near it. The weights decide how smoothly a joint bends.
- Lottie
- A JSON animation format (bodymovin) that plays natively on the web, iOS and Android. Vector shapes and transforms travel; raster effects do not.
- Mask
- A vector path on a layer that limits what part of it is visible. Feather softens the edge; mask modes add, subtract and intersect several paths.
- MOGRT
- Motion Graphics Template: a composition with a few fields exposed so an editor can change the text or colours without opening the animation.
- Motion path
- The spatial trajectory an animated position follows, drawn as a line through its keyframes. Editing the path's Bézier handles changes the route without touching the timing.
- Motion tracking
- Following a feature in footage from frame to frame and writing its position as keyframes, so graphics can be attached to something that moves.
- Null object
- An invisible layer with a full transform, used as a parent so a group of layers can be moved, rotated or scaled together.
- Parenting
- Linking one layer's transform to another's so the child inherits the parent's position, rotation and scale, on top of its own.
- Pick-whip
- A drag gesture that links one thing to another: a layer to a parent, or a property to an expression that reads another property.
- Pre-composition
- A composition nested inside another as a single layer. Its layers render to their own buffer and composite as one unit, which is how complex scenes stay editable.
- Puppet pin
- A control point placed on a mesh generated over flat artwork. Dragging the pin deforms the artwork around it, so a drawing can bend without a skeleton.
- Range selector
- The part of a text animator that decides which characters, words or lines an animation applies to. Animating the selector, not the property, is what makes text arrive letter by letter.
- Render snapshot
- A flat, immutable description of one frame, produced by sampling every animated value at one time. Everything that draws reads from it, so preview and export cannot disagree.
- Repeater
- A shape operator that fans one shape into many copies, each offset by a transform, so a single dot becomes a ring, a grid or a spiral.
- Shape layer
- A layer made of vector paths with fills and strokes, plus a chain of operators that modify them. Resolution-independent and animatable down to the vertex.
- Shy and solo
- Two timeline switches that people confuse. Shy hides a layer from the timeline list without hiding it in the picture. Solo renders only the soloed layers.
- Speed ramp
- A smooth change in a clip's playback speed: slowing into a moment and speeding back out, rather than a hard cut to slow motion.
- SVG
- Scalable Vector Graphics, the web's vector format. Paths, fills, strokes and groups in XML that any browser draws at any size.
- Text animator
- A set of property offsets applied to a text layer through a selector, so each glyph can move, fade, scale or rotate on its own schedule.
- Time remapping
- Keyframing a clip's internal time: which source frame plays at which composition frame. Freezes, reverses and ramps are all time-remap curves.
- Track matte
- Using one layer's luminance or alpha to decide another layer's transparency. A luma matte uses brightness; an alpha matte uses the shape.
- Trim paths
- A shape operator that reveals only part of a stroke, from a start to an end percentage. Animating End draws a line on; animating Offset chases a dash along it.
- Two-node camera
- A camera with a point of interest it always looks at. Move the camera and it keeps aiming at the subject; move the point and the camera turns to follow.
- WebGPU and WebGL2
- Two GPU programming interfaces. WebGPU is the newer one with compute shaders; WebGL2 is the older fallback available almost everywhere.