Motion Design

Motion Design

Purpose

Design the motion language for a feature or system, including transition specs, micro-interaction definitions, choreography principles, and reduced-motion alternatives.

Inputs

• Feature or component requiring motion design
• Existing animation patterns in the project (if any)
• Performance constraints (target FPS, device capabilities)
• Accessibility requirements (prefers-reduced-motion support)

Process

Step 1: Identify Motion Opportunities

Catalog where motion adds meaning:

• State transitions: Loading → loaded, collapsed → expanded, hidden → visible
• Navigation transitions: Screen push/pop, modal present/dismiss, tab switch
• Feedback responses: Button press, form submission, error shake, success check
• Attention guidance: New item appears, notification badge, scroll-to-target
• Data changes: List reorder, item add/remove, value count-up

Step 2: Define Motion Principles

Establish the motion language for this project:

• Duration scale: Micro (100ms), short (200ms), medium (300ms), long (500ms)
• Easing curves: Enter (ease-out), exit (ease-in), standard (ease-in-out)
• Stagger: Delay between sequential items (50-100ms per item, max 5 items)
• Distance: How far elements travel relative to their size

Step 3: Spec Each Animation

For each motion opportunity, define:

• Property: What changes (opacity, transform, height, color)
• Duration: How long (from the duration scale)
• Easing: Which curve (from the easing set)
• Delay: When it starts relative to the trigger
• Direction: Where it moves from/to

Step 4: Design Choreography

For multi-element transitions:

• Entrance order: What appears first, second, third
• Stagger timing: Delay between each element
• Shared elements: Elements that morph between states
• Exit choreography: Reverse of entrance, or distinct exit pattern

Step 5: Reduced-Motion Alternatives

For every animation, define the prefers-reduced-motion alternative:

• Instant transitions: Replace motion with opacity crossfade
• Remove parallax: Static positioning instead
• Simplify choreography: Single fade-in instead of staggered entrance
• Keep functional animation: Loading spinners stay (they communicate state)

Step 6: Performance Considerations

Verify motion feasibility:

• Composite-only properties: Prefer transform and opacity (GPU-accelerated)
• Avoid layout thrash: Don't animate width, height, top, left
• will-change hints: Add for elements that will animate
• 60fps budget: Each frame must complete in <16.6ms

Output Format

# Motion Design Specification

## Motion Principles
| Property | Value | Usage |
|----------|-------|-------|
| Duration (micro) | 100ms | Hover, focus |
| Duration (short) | 200ms | Expand, collapse |
| Duration (medium) | 300ms | Page transitions |
| Ease (enter) | cubic-bezier(0, 0, 0.2, 1) | Elements appearing |
| Ease (exit) | cubic-bezier(0.4, 0, 1, 1) | Elements leaving |
| Stagger | 50ms | List items |

## Animation Specs

### [Component/Interaction Name]
**Trigger:** [User action or state change]
**Property:** [What changes]
**From → To:** [Start value → End value]
**Duration:** [From scale]
**Easing:** [From set]
**Reduced motion:** [Alternative]

## Choreography
### [Transition Name]
1. [Element] fades in at 0ms (200ms, ease-out)
2. [Element] slides up at 50ms (200ms, ease-out)
3. [Element] fades in at 100ms (200ms, ease-out)

## Reduced Motion Summary
| Animation | Full Motion | Reduced Motion |
|-----------|------------|----------------|
| Page enter | Slide + fade | Instant fade |
| List stagger | Staggered slide-up | Single fade |
| Loading | Spinner | Spinner (kept) |

Quality Checks

• Every animation has a purpose (communicates state change, guides attention, or provides feedback)
• Duration and easing values come from the defined scale, not arbitrary values
• Every animation has a prefers-reduced-motion alternative
• Animations use composite-only properties (transform, opacity) where possible
• Stagger timing doesn't exceed 5 items (cap the stagger, fade the rest)
• No animation exceeds 500ms (users perceive delays >400ms as laggy)

Evolution Notes