yawn/docs/guide/cameras.md

Cameras and controls

Every camera allocates generic cameras, cameraMatrices, and transform rows. Camera handles precompute the view-projection matrix when lens or transform values change, so the forward vertex shader performs four dot products instead of rebuilding the camera projection for every vertex.

Shared lens and projection controls

const camera = new Camera(scene, {
  fov: Math.PI / 3,
  near: 0.05,
  far: 2000,
  focalLength: 50,
  aperture: 2.8,
  focusDistance: 8,
});
await camera.ready;

camera.projection = "orthographic";
camera.orthoSize = 12;
camera.projection = "perspective";

fov, aspect, near, far, orthoSize, focalLength, aperture, focusDistance, and sensorWidth all write the camera's shared row.

Arc rotate

const orbit = new ArcRotateCamera(scene, {
  alpha: 0,
  beta: Math.PI / 3,
  radius: 6,
  target: mesh,
  controls: {
    element: canvas,
    pointer: true,      // left orbit, right pan, wheel zoom
    controller: true,  // sticks + triggers
  },
});
await orbit.ready;

Free spectator camera

const free = new FreeCamera(scene, {
  position: [0, 1, 5],
  controls: {
    element: canvas,
    keyboard: true,    // WASD + Space/Ctrl
    pointer: true,     // click for pointer lock, mouse to look
    controller: true,
    speed: 6,
  },
});
await free.ready;

Follow a character

const follow = new FollowCamera(scene, {
  target: player,
  distance: 5,
  height: 1.8,
  smoothing: 0.12,
});
await follow.ready;

follow.target = anotherPlayer;
follow.distance = 7;
follow.stop();
follow.start();

The input and follow loops never post camera updates to core: they mutate the position, rotor, camera, and derived matrix rows directly in shared memory.

<script setup> import Playground from "../.vitepress/Playground.vue"; </script>