PinballBuilder

Data-driven, in-game placer that spawns fully-wired pinball elements on request.

What it does

Listens for a family of pinballBuilder.add* events and spawns a complete entity at the requested table coordinates — MeshPrimitive + Shadow + Physics plus the matching behavior component — then emits pinballBuilder.entityAdded. It supports bumpers, walls, rails (elevated wires), ramps (tilted floor segments), spinners, and mouse-holes/saucers. It also drives freehand drawing: pinballBuilder.setDrawMode toggles draw mode (echoed via pinballBuilder.drawModeChanged), and pinballBuilder.drawPath smooths a raw pointer polyline (Ramer–Douglas–Peucker simplify → Catmull-Rom spline → uniform arc-length resample) and chains one rail/wall segment per interval to turn a freehand line into a clean curved track.

Use it in a scene

A scene is just data — a list of entities, each with its components. At startup the SceneLoader turns this JSON into a live world; edit the file and reload to rebuild it.

Fastest path

bjs download scene PinballBuilder

Pulls this exact scene into your project and runs it — no copy-paste. Add --all to grab the components and assets it needs too.

Or build it from scratch with the bjs CLI:

1Scaffold a project
```
npm create @babylonjsmarket/arcade@latest my-game
```
World, renderer, and dev server — ready to run.
2Install dependencies
```
cd my-game && npm install
```
3Add PinballBuilder
```
bjs download PinballBuilder
```
Copies its source into src/ so the scene resolves.
First time? Run bjs login once.
4Paste the scene into src/scenes/arcade-room.ts and run
```
npm run dev
```
SceneLoader builds the world from the JSON; reload to rebuild.

JSON

{
  "entities": {
    "Table": {
      "components": {
        "PinballTable": { "width": 16, "depth": 33.2 }
      }
    },
    "Builder": {
      "tags": ["builder"],
      "components": {
        "PinballBuilder": { "defaultBumperPoints": 250, "defaultBumperDiameter": 1.78 }
      }
    }
  }
}

Props

defaultBumperPoints (number, default 250) — points awarded by a newly spawned pop-bumper when the request omits points.
defaultBumperDiameter (number, default 1.78) — diameter of a newly spawned pop-bumper when the request omits diameter.

(Per-kind id counters and the drawMode/drawKind flags are runtime state, not serialized inputs.)

Events

Emits pinballBuilder.entityAdded — { entityId, kind } after each spawn.
Emits pinballBuilder.drawModeChanged — { enabled, kind } after draw mode toggles.
Listens for pinballBuilder.addBumper, addWall, addRail, addRamp, addSpinner, addMouseHole — each with { x, z, ... } to spawn that element.
Listens for pinballBuilder.setDrawMode — { enabled, kind? }.
Listens for pinballBuilder.drawPath — { points: [{x,z}, ...], kind, ... }.

Dependencies

MeshPrimitive — the visible geometry of every spawned element. Bumper, Spinner, MouseHole — the behavior components attached to the matching spawns. PinballTable — the table coordinate space the requests are placed into. (Shadow + Physics from the arcade package are attached at spawn time via dynamic import.)

Notes

Element classes import from arcade lazily (dynamic import) so the file stays declaration-only on the surface and physics isn't pulled until something is spawned.
Spinners are spawned without Physics so the ball passes through; the Spinner system detects contact by XZ proximity.
A wall is a thick opaque perimeter box; a rail is a thin chrome wire suspended above the playfield; a ramp is an angled solid floor segment built into the playfield.