zustand-entities_skill

Overview

This skill shows how to use Zustand as a lightweight state store for managing entities in r3f projects. It presents a pragmatic pattern: keep entities in a store array, let systems access state non-reactively for runtime updates, and let React components subscribe for rendering. The approach is intentionally simple — not a full ECS — and targets small games and prototypes where ease and speed matter.

How this skill works

Create a Zustand store that holds arrays of entity objects. Systems (useFrame) call getState() to iterate and mutate entities without causing React re-renders, while component trees use the store selector hooks to reactively track additions or removals. Memoize entity components so rendering only happens when the subscribed slice changes, and perform per-frame logic directly against the stored entity data.

When to use it

• Small games, prototypes, or demos where developer speed is more important than a full ECS.
• Projects that need simple global entity lists with per-frame updates via useFrame.
• When you want deterministic, non-reactive systems logic separate from React rendering.
• When you prefer minimal setup and TypeScript-friendly patterns over complex tooling.

Best practices

• Keep entities as plain objects with stable IDs and minimal mutable state.
• Use useStore(selector) in components to subscribe only to the list or slice needed.
• Use getState() inside systems (useFrame) to avoid unnecessary React re-renders.
• Memoize entity-render components (React.memo) to reduce render churn.
• Limit the number of entities or partition into focused arrays to keep per-frame loops cheap.

Example use cases

• A small 2D/3D arcade game with a few dozen moving characters or bullets.
• Prototyping enemy patrols and projectiles before migrating to an ECS if needed.
• Managing spawn/despawn of objects in a scene while systems update positions and physics.
• Coordinating UI-driven entity creation and removal with fast, predictable game loops.