Camera

The scene camera, reached at scene.camera. It's a Node, so the full transform surface works — position, eulerAngles, lookAt, forward. On top of that it exposes projection reads and screen→world ray helpers for picking.

You never construct one: every Scene creates its own camera (overlays share the parent's). In an ARScene the camera is driven by device tracking — read it, don't place it.

At a glance

TypeScript

scene.camera.position = [0, 2, 4]
scene.camera.lookAt([0, 0.5, 0])

scene.addEventListener('touchstart', ev => {
  const ray = scene.camera.getRay(ev.clientX, ev.clientY)
  const hit = Physics.raycast(ray.origin, ray.dir)
  if (hit) console.log('tapped', hit.node?.name)
})

Projection reads

TypeScript

camera.fov               // vertical field of view, DEGREES (read-only)
camera.horizontalFov     // horizontal field of view, degrees (read-only)
camera.displaySize       // [width, height] of the 3D viewport, px (read-only)
camera.projectionMatrix  // Float32Array(16), live — the host updates it in place on resize/fov change

Screen → world rays

TypeScript

camera.getViewDirection(screenX, screenY): Vec3   // world-space ray direction through a screen point
camera.getRay(screenX, screenY): Ray              // origin = camera.worldPosition, dir = view direction

Screen coordinates are logical px — the same space as ev.clientX / ev.clientY. getRay pairs directly with Physics.raycast for tap-picking; Ray is documented in ray-plane-noise.

Note

there is no worldToScreen helper — the inverse projection is only available raw, via projectionMatrix + the camera's worldMatrix.

Pitfalls

TypeScript

// ✗ moving the camera in an ARScene — tracking overwrites it every frame
arScene.camera.position = [0, 2, 4]
// ✓ move the WORLD instead: parent content under scene.root and place that

Camera

At a glance

Projection reads

Screen → world rays

Pitfalls

See also