Verbs — bringing it to life

Verbs are the script. Each one names an entity and animates it. They run top-to-bottom, one after another (use par for simultaneous).

Almost every verb takes two optional trailing arguments:

move(sun, (900, 400), 0.8, smooth);
//                     ^dur  ^easing

[dur] — how long, in seconds (there’s a sensible default).
[ease] — the motion curve: linear, smooth, in, out, back, bounce, elastic, spring (see Colour & style).

Attention

flash(sun, cyan);  // -> flash to a colour, then restore
pulse(sun);        // -> quick grow-and-settle "look here"
shake(sun);        // -> horizontal shake, an "error/no" gesture
spin(sun, 360);    // -> spin about its centre

Motion

move(p,  (900, 400));   // -> glide to an absolute point
shift(p, (0, -120));    // -> move by a delta (relative)
scale(r, 1.4);          // -> animate uniform scale to 1.4x
rotate(r, 45);          // -> rotate by 45 degrees
grow(arrow, (500, 200));// -> animate a line/arrow endpoint (draws or retargets)
cycle(x, y, z, 0.8, 90, smooth); // -> x→y→z→x along arcs

cycle(a, b, c, …, [dur], [arc], [ease]) moves every entity into the next one’s position and the last into the first. The path arc is in degrees and defaults to 90; pass 0 for straight paths. Repeated calls compose, making it useful for symbol rearrangements, card carousels, and CyclicReplace-style moves.

Relationship motion

Three verbs cover motion that would otherwise require many coordinated keyframes:

attach(label, marker, (0,-36));       // label follows marker
travel(marker, route, 2, smooth);
become(marker, nodeBlueprint, 0.8);   // same id, new visual state
attach(label, none);                  // release at the settled position
turn(nodeGroup, marker, 20, 0.6, out);// shared group pivot

attach is persistent until released. become interpolates compatible shapes and safely crossfades other pairs, always settling on the exact declared blueprint. turn accepts one entity or a tag and rotates its members around a point or entity pivot. See Motion graphics for the full design rules and a copyable V2 Reel.

▶ Watch: motion

Ambient motion and path flow

particles(bubbles, glass, 24, 5, 7);
link(pipe, glass, tank, 35);
untraced(pipe);

par {
  wander(bubbles, 6);              // always stays inside glass
  seq { draw(pipe); flow(pipe, 1); }
}

wander is deterministic: the same optional particle seed gives the same placement and motion in preview and in the final recording. It occupies the duration you give it, so run it in par with the story it should accompany. flow sends a temporary luminous pulse over any line, arrow, curve, spline, arc, or tracked link; it is useful for a signal, energy, traffic, or simply directing attention.

travel(marker, path, dur, smooth) moves the actual marker once along that same kind of path and leaves it at the endpoint. Use flow for temporary emphasis and travel when object identity and the stopping point matter:

plot(curve, (180,620), 90, 140, "1-exp(-x)", (0,4));
dot(marker, (180,620), 7);
par { draw(curve, 2, out); travel(marker, curve, 2, out); }

For a persistent layout change, keep the same particle ids:

rect(chamber, (540,500), 600, 260);
particles(gas, chamber, 48, 5, 17, "grid");
arrange(gas, chamber, "random", 2.5, smooth);
arrange(gas, chamber, "grid", 2.5, smooth); // exact ordered return

circle(orbit, (900,500), 150);
arrange(gas, orbit, "ring", 1.2, smooth);    // move and stop radially

arrange also accepts a different circle/rectangle container, which makes a free expansion readable without moving every dot by hand. A random layout uses independent seeded curved routes: the result is reproducible and scrubbable, but does not look like every particle followed the same ruler.

For a complete creator-oriented treatment of persistent motion, arrival, settling, and the difference between travel and flow, see Motion graphics — move ideas, not layers.

For shape continuity, morph(a,b) preserves topology: graph/line paths remain open, while circles and other closed outlines remain closed. This prevents an unwanted diagonal chord when a plot becomes a connector or guide line.

For a persistent comparison style, use dashed(id, [dash], [gap]) before the timeline. It is a base Manic modifier—not a calculus feature—so the same 16/10-pixel default pattern works on a plot, guide line, link, arrow, curve, spline, coil, or plain arc. Increase both values for a calmer large-format dash; keep the gap smaller than the dash when the curve must remain easy to follow.

Content & colour

say(cap, "next step");     // -> crossfade a text entity to new words
recolor(sun, lime, 0.5);   // -> permanently animate the colour

Rewrite an equation without rebuilding it

Declare one real LaTeX equation, then supply each mathematically correct state:

equation(work, (cx, 300), `x^2+2x=3`, 54);
rewrite(work, `x^2+2x+1=4`, 0.9, smooth);
rewrite(work, `(x+1)^2=4`, 0.9, smooth);
rewrite(work, `x=-1\pm2`, 0.9, smooth);

rewrite is visual, not a computer-algebra system: it never invents or verifies a step. Equal RaTeX parts retain identity and travel smoothly. Matching respects reading order, coarse layout roles—main line, exponent, numerator, denominator, fraction rule, and other structure—and RaTeX math-style depth. An identical character therefore cannot change mathematical jobs or jump between levels of a nested exponent. This also protects logarithm bases, operator limits, and derivative orders. If one side gains or loses fraction, radical, or grouping structure, that side leaves before the replacement enters while the compatible side and equality remain continuous. Globally incompatible states, such as a matrix becoming a compact formula, use a staged whole-equation dissolve with only a short, dim overlap. When unmatched source and target glyphs are a replacement, the old glyph leaves before the new one becomes readable; pure additions still enter immediately. Semantic \textcolor roles follow the authored formula, and the final frame is always the exact target LaTeX. No flag or alternate verb is required. Keep one equation id for the whole derivation, write readable steps, and use wait between them when the viewer needs time to absorb a result.

For a plot or diagram that changes with the same step, place rewrite and the related motion in par. Existing equations are unaffected unless this verb is used.

▶ Watch: text

The escape hatch — `to` / `set`

Named verbs are shortcuts. to animates any single property, for whatever isn’t pre-named:

to(sun, opacity, 0.3, 0.5);   // animate opacity to 0.3 over 0.5s
to(sun, rot, 90);             // rotation to 90 degrees

Properties: pos, color, opacity, scale, rot, trace, hue.

Move the camera

cam((300, 200), 1.0);   // pan the camera centre
zoom(1.6, 0.8);         // zoom to 1.6x

The camera moves the whole world, so a caption or counter would slide off with it. Mark it sticky(id) to pin it to the screen and keep it readable through the move.

One verb, a whole group

If a name refers to a tag (a group) instead of a single entity, the verb runs on every member at once. This is how you animate a whole graph, table, or loop-generated set in one line:

hidden(g.nodes);     // every node, at t=0
draw(g.edges);       // trace every edge on together
flash(a.cells, cyan);// flash all array cells

More on grouping in the Kits chapter. Next, control when things happen → Timing.

manic — the manual