secondary-action-mastery

Secondary action adds life to a scene without distracting from the main action. A character walking (primary) while whistling and swinging their arms (secondary). A button pressing (primary) with a subtle ripple effect (secondary). It's the difference between functional animation and rich, immersive motion.

Subordination principle: Secondary action must never compete with primary action. If viewers watch the secondary instead of primary, you've failed. The supporting role must remain supporting.

Reinforcement function: Good secondary action reinforces the primary action's meaning. It doesn't just add motion—it adds dimension to the story being told.

在豐富主要動畫、添加支援細節、創建運動深度或使場景感覺生動而不分散主要動作時使用。 來源：dylantarre/animation-principles。