manus-skills/.kortix/opencode/skills/media/motion-graphics/rules/timing-and-easing.md

Timing and Easing Rules

The 12 Principles Applied to Motion Graphics

1. Timing

The number of frames for an action determines perception:

• Fewer frames = faster, snappier
• More frames = slower, heavier

2. Ease In / Ease Out (Slow In / Slow Out)

Objects accelerate and decelerate naturally:

# Natural motion
rate_func=smooth  # Default, good for most

# Dramatic entrance (fast start, slow end)
rate_func=ease_out_cubic

# Dramatic exit (slow start, fast end)
rate_func=ease_in_cubic

Manim Rate Functions Reference

Standard Easing

Rate Function	Feel	Best For
linear	Mechanical	Loading bars, clocks
smooth	Natural	General purpose
rush_into	Aggressive	Exits, impacts
rush_from	Dramatic	Entrances

Cubic Family

Rate Function	Curve	Use Case
ease_in_cubic	Slow→Fast	Exits
ease_out_cubic	Fast→Slow	Entrances
ease_in_out_cubic	Slow→Fast→Slow	Smooth transitions

Expo Family (More Dramatic)

Rate Function	Effect	Use Case
ease_in_expo	Very slow start	Suspense
ease_out_expo	Snappy stop	Impact

Bounce and Back

Rate Function	Effect	Use Case
ease_out_bounce	Bouncy landing	Playful
ease_out_back	Overshoot	Pop-in effects
ease_in_back	Wind-up	Anticipation

Special Functions

Rate Function	Effect	Use Case
there_and_back	Go and return	Pulses
double_smooth	Extra smooth	Gentle loops
lingering	Slow at end	Emphasis

Timing by Animation Type

Entrances

# Pop in (impactful)
run_time=0.3, rate_func=ease_out_back

# Slide in (smooth)
run_time=0.5, rate_func=ease_out_cubic

# Fade in (gentle)
run_time=0.7, rate_func=smooth

Exits

# Quick exit
run_time=0.3, rate_func=ease_in_cubic

# Dramatic exit
run_time=0.5, rate_func=ease_in_expo

# Gentle exit
run_time=0.7, rate_func=smooth

Emphasis

# Scale pulse
run_time=0.4, rate_func=there_and_back

# Color flash
run_time=0.3, rate_func=ease_out_cubic

# Shake/wiggle
run_time=0.5, rate_func=wiggle

Transforms

# Shape morph
run_time=1.0, rate_func=smooth

# Position change
run_time=0.5, rate_func=ease_in_out_cubic

# Dramatic transformation
run_time=1.5, rate_func=ease_in_out_expo

Duration Guidelines

By Content Type

Animation	Duration
Logo reveal	1-2s
Title entrance	0.5-1s
Text word	0.3-0.5s
Icon pop	0.2-0.4s
Scene transition	0.5-1s
Background change	0.3-0.5s

By Emotional Tone

Tone	Speed Multiplier
Energetic	0.7x
Normal	1.0x
Calm	1.3x
Dramatic	1.5x
Suspenseful	2.0x

Custom Rate Functions

Creating Custom Easing

def custom_ease(t):
    """
    t goes from 0 to 1
    Return value should also be 0 to 1
    """
    # Example: slow middle, fast ends
    return t ** 2 if t < 0.5 else 1 - (1 - t) ** 2

self.play(obj.animate.move_to(RIGHT), rate_func=custom_ease)

Bezier Curve Easing

from manim import bezier

# Custom bezier curve
custom = bezier([0, 0, 0.2, 1])  # Control points
self.play(obj.animate.shift(RIGHT), rate_func=custom)

Timing Patterns

The "Snap" Pattern

Quick movement with overshoot:

self.play(
    obj.animate.move_to(target),
    rate_func=ease_out_back,
    run_time=0.3
)

The "Slide" Pattern

Smooth, professional movement:

self.play(
    obj.animate.move_to(target),
    rate_func=ease_in_out_cubic,
    run_time=0.7
)

The "Bounce" Pattern

Playful, energetic:

self.play(
    obj.animate.move_to(target),
    rate_func=ease_out_bounce,
    run_time=0.8
)

The "Anticipation" Pattern

Wind-up before action:

# Anticipation
self.play(
    obj.animate.shift(LEFT * 0.2),
    rate_func=ease_out_cubic,
    run_time=0.2
)
# Main action
self.play(
    obj.animate.shift(RIGHT * 5),
    rate_func=ease_in_cubic,
    run_time=0.3
)

Common Mistakes

DON'T: Same timing for everything

# BAD - Monotonous
self.play(obj1.animate.shift(UP), run_time=1)
self.play(obj2.animate.shift(UP), run_time=1)
self.play(obj3.animate.shift(UP), run_time=1)

DO: Vary timing for interest

# GOOD - Dynamic
self.play(obj1.animate.shift(UP), run_time=0.5)
self.play(obj2.animate.shift(UP), run_time=0.3)
self.play(obj3.animate.shift(UP), run_time=0.7)

DON'T: Linear easing for organic motion

# BAD - Robotic
self.play(logo.animate.move_to(ORIGIN), rate_func=linear)

DO: Use appropriate easing

# GOOD - Natural
self.play(logo.animate.move_to(ORIGIN), rate_func=ease_out_cubic)