Bumper

Bumper

A proximity-based scoring trigger: when a ball crosses its hit radius it awards points to a score owner.

What it does

Each bumper entity owns its own hit radius and point value. The system runs an XZ distance check against every ball-tagged entity and, the frame a ball enters hitRadius, emits bumper.hit plus score.add to award points to ownerEntity. A per-bumper-per-ball debounce keeps a slow rolling ball from re-triggering every frame — the flag clears only once the ball moves beyond releaseRadius. The system is renderer-agnostic: it reads MeshPrimitive positions only and never touches Babylon or Havok, leaving the physical deflection to a Physics component on the same entity.

Use it in a scene

bjs download scene Bumper

{
  "ScoreState": {
    "components": {
      "Score": { "defaultPoints": 100, "scores": { "Player": 0 } }
    }
  },
  "Bumper_Center": {
    "components": {
      "MeshPrimitive": {
        "primitive": "cylinder",
        "diameter": 1.78,
        "height": 1.5,
        "position": [0, 0.75, 0],
        "material": { "diffuseColor": [0.95, 0.35, 0.65], "emissiveColor": [0.55, 0.15, 0.35] }
      },
      "Physics": { "shapeType": "capsule", "motionType": "static", "restitution": 0.95, "friction": 0.02 },
      "Bumper": { "points": 500, "hitRadius": 1.25, "releaseRadius": 1.7, "ownerEntity": "Player" }
    }
  }
}

Props

• points (number, default 100) — points awarded to ownerEntity per hit.
• hitRadius (number, default 1.4) — XZ distance at which a contact registers.
• releaseRadius (number, default 1.9) — XZ distance at which the contact flag resets, allowing a new hit.
• ownerEntity (string, default 'Player') — score recipient, keyed by Score's entity map.

Events

• emits bumper.hit — when a ball enters hitRadius; payload { bumperId, ballId, points }.
• emits score.add — alongside the hit, to credit ownerEntity with points.

Dependencies

MeshPrimitive — supplies the bumper and ball positions for the distance check. Score — receives the score.add event and tracks the owner's total.

Notes

• Set releaseRadius larger than hitRadius so a ball lingering at the edge can't chatter on/off.
• The bounce itself is not done here — add a Physics body (e.g. static with high restitution) on the same entity for the actual deflection.
• The in-contact debounce state is runtime-only, kept off the serializable Component.