health-bars - SKILL.md Agent Skill

name: health-bars description: Display health bars above characters using CSS styling.

Health Bars

Display health bars above characters using CSS styling.

Technique

Use Drei's Html component to render styled health bars in 3D space. Update the health bar width by manipulating the DOM element's transform: scaleX() via a ref in useFrame.

Key Concepts

Html from @react-three/drei with center and distanceFactor props
Use refs to directly manipulate DOM styles for performance
scaleX transform for smooth width changes with CSS transitions
Style with CSS (gradients, borders, skew transforms)

Usage

const healthRef = useRef<HTMLDivElement>(null)

useFrame(() => {
  healthRef.current.style.transform = `scaleX(${healthPercent})`
}, { fps: 1 })

<Html center position-y={1.5} distanceFactor={5}>
  <div className="bg-red-500">
    <div ref={healthRef} className="bg-green-500 origin-left transition-transform" />
  </div>
</Html>

This skill is part of verekia's r3f-gamedev.