video-motion-graphics（视频动态图形）

Video Motion Graphics

Apply Disney's 12 animation principles to After Effects, Premiere Pro, and video motion design.

Quick Reference

Principle Applications

Squash & Stretch: Use scale property with different X/Y values. Overshoot expressions create elastic motion. Shape layers deform more naturally than pre-comps for organic squash.

Anticipation: Add 2-4 frames of reverse motion before primary action. Wind-up for reveals—slight scale down before scale up. Position anticipation: move opposite direction first.

Staging: Use depth of field to direct focus. Vignettes frame important content. Motion blur on secondary elements. Composition leads eye to focal point.

Straight Ahead vs Pose to Pose: Traditional frame-by-frame for character animation. Keyframe-based for graphic animation. Most motion graphics are pose-to-pose with expression refinement.

Follow Through & Overlapping: Use valueAtTime() expressions for lag. Stagger layer animation with offset. Secondary elements continue 4-8 frames past primary stop. Parent/child relationships with delayed response.

Slow In / Slow Out: Master the Graph Editor—never use linear keyframes. Easy Ease is starting point, customize curves. Bezier handles control acceleration. Speed graph shows velocity.

Arc: Enable motion path editing. Auto-orient rotation to path. Add roving keyframes for smooth arcs. Natural motion rarely travels in straight lines.

Secondary Action: Particles respond to primary motion. Shadows and reflections follow. Background elements shift with parallax. Audio waveforms drive visual elements.

Timing: 24fps: Cinematic feel, motion blur essential. 30fps: Broadcast standard, smoother. 60fps: Digital-first, very smooth. Hold frames (2s, 3s) for stylized timing.

Exaggeration: Motion graphics can push further than reality. Scale overshoots to 120-150%. Rotation extends past final. Color and effects can punctuate exaggeration.

Solid Drawing: 3D layers maintain spatial consistency. Parallax creates depth hierarchy. Consistent light direction across elements. Z-positioning creates believable space.

Appeal: Smooth interpolation, no jarring cuts. Color grading unifies composition. Typography has weight and personality. Motion feels intentional and professional.

After Effects Techniques

Overshoot Expression

// Apply to any property for elastic overshoot
freq = 3;
decay = 5;
n = 0;
if (numKeys > 0) {
    n = nearestKey(time).index;
    if (key(n).time > time) n--;
}
if (n > 0) {
    t = time - key(n).time;
    amp = velocityAtTime(key(n).time - .001);
    w = freq * Math.PI * 2;
    value + amp * (Math.sin(t * w) / Math.exp(decay * t) / w);
} else {
    value;
}

Stagger Expression

// Apply delay based on layer index
delay = 0.1;
d = delay * (index - 1);
time - d;

Timing Reference

Export Considerations

• Preview at final framerate
• Enable motion blur for fast motion
• Check timing at 1x speed, not RAM preview
• Account for broadcast safe areas
• Test on target display format