Add SAB-backed rotor transforms and smooth camera controls

Amp-Thread-ID: https://ampcode.com/threads/T-01a01ff8-b91f-724f-8952-f07c6b5042fd
Co-authored-by: Heaust Azure <heaust.azure@gmail.com>

docs/.vitepress/Playground.vue

@@ -496,6 +496,7 @@ canvas {
   height: 100%;
   display: block;
   object-fit: contain;
+  touch-action: none;
 }
 .output {
   position: absolute;

docs/.vitepress/playgrounds.js

@@ -61,8 +61,8 @@ log("Pointer movement mutates nodePositions; no worker message is sent.");
 
 const move = (event) => {
   const bounds = canvas.getBoundingClientRect();
-  mesh.position[0] = ((event.clientX - bounds.left) / bounds.width - 0.5) * 1.4;
-  mesh.position[1] = (0.5 - (event.clientY - bounds.top) / bounds.height) * 1.2;
+  mesh.position.x = ((event.clientX - bounds.left) / bounds.width - 0.5) * 1.4;
+  mesh.position.y = (0.5 - (event.clientY - bounds.top) / bounds.height) * 1.2;
 };
 canvas.addEventListener("pointermove", move);
 
@@ -270,13 +270,35 @@ log("HDR → exposure → color grading → FXAA → canvas");
 
 return { scene, mesh, exposure, grade, fxaa, dispose: () => scene.dispose() };`;
 
-const importing = `import { ArcRotateCamera, Picking, Scene, importGltf } from "@yawn/handles";
+const importing = `import { AmbientLight, ArcRotateCamera, PointLight, Picking, Scene, importGltf } from "@yawn/handles";
 
 const scene = new Scene(canvas, { hdr: true, arenaBytes: 384 * 1024 * 1024 });
 await scene.ready;
+scene.array("sceneAccent").row(0).set([1, 1, 1, 1]);
 log("Importing /models/sponza.glb in the importer worker…");
 const meshes = await importGltf(scene, "/models/sponza.glb");
 
+// Add a warm ambient/key/fill setup without changing the authored transforms.
+const lights = [
+  new AmbientLight(scene, {
+    color: [1, 0.93, 0.82],
+    intensity: 0.18,
+  }),
+  new PointLight(scene, {
+    position: [-10, 14, -4],
+    color: [1, 0.72, 0.5],
+    intensity: 2,
+    range: 28,
+  }),
+  new PointLight(scene, {
+    position: [9, 10, 6],
+    color: [1, 0.9, 0.75],
+    intensity: 1.5,
+    range: 24,
+  }),
+];
+await Promise.all(lights.map((light) => light.ready));
+
 const target = [0, 8, 0];
 const camera = new ArcRotateCamera(scene, {
   targetPosition: target,
@@ -305,6 +327,7 @@ await pick();
 return {
   scene,
   meshes,
+  lights,
   camera,
   picking,
   async dispose() {

docs/guide/cameras.md

@@ -72,7 +72,7 @@ follow.stop();
 follow.start();
 ```
 
-The input and follow loops never post camera updates to core: they mutate the position, quaternion, camera, and derived matrix rows directly in shared memory.
+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.
 
 <Playground example="cameras" />
 

docs/guide/importing-and-picking.md

@@ -8,7 +8,7 @@ The shared importer worker fetches and parses glTF/GLB, then the response hydrat
 import { importGltf } from "@yawn/handles";
 
 const meshes = await importGltf(scene, "/models/sponza.glb");
-meshes[0].position[1] = 0.5;
+meshes[0].position.y = 0.5;
 ```
 
 The importer handles triangle primitives, external/data buffers, standard vertex attributes, indices, node transforms, and metallic-roughness values. Application-specific extensions remain application policy.
@@ -34,7 +34,7 @@ If row allocations relocated since `Picking` was created, refresh its shared des
 await picking.refresh();
 ```
 
-The playground below imports the repository's full LFS-backed `sponza.glb` in the importer worker, preserves its authored transforms, places an arc camera in its coordinate system, and sends a real ray to the BVH worker. Click the preview to pick again.
+The playground below imports the repository's full LFS-backed `sponza.glb` in the importer worker, preserves its authored transforms, adds neutral warm lighting, places an arc camera in its coordinate system, and sends a real ray to the BVH worker. Click the preview to pick again.
 
 <Playground example="importing" />
 

docs/guide/lights.md

@@ -11,7 +11,7 @@ const point = new PointLight(scene, {
 });
 
 const sun = new DirectionalLight(scene, {
-  quaternion: [0.2, 0, 0, 0.98],
+  rotor: [0.2, 0, 0, 0.98],
   color: [1, 0.95, 0.8],
   intensity: 3,
 });

docs/guide/scene-and-sab.md

@@ -1,6 +1,6 @@
 # Scene and shared data
 
-Think of every handle as an array index, not an object mirrored into core. `Node.position`, `Node.quaternion`, and `Node.scale` are views into separate flat SOA arrays.
+Think of every handle as an array index, not an object mirrored into core. `Node.position`, `Node.rotor`, and `Node.scale` are component views into separate flat SOA arrays.
 
 ## Direct transform movement
 
@@ -11,12 +11,12 @@ const pivot = new Node(scene, { position: [0, 1, 0] });
 await pivot.ready;
 
 canvas.addEventListener("pointermove", (event) => {
-  pivot.position[0] += event.movementX * 0.002;
-  pivot.position[1] -= event.movementY * 0.002;
+  pivot.position.x += event.movementX * 0.002;
+  pivot.position.y -= event.movementY * 0.002;
 });
 ```
 
-The pointer handler sends no messages. The typed-array view points directly into the arena shared with the render worker. The camera helpers use this same pattern; see [Cameras and controls](/guide/cameras).
+The pointer handler sends no messages. Each component property reads or writes its lane in the arena shared with the render worker. Replace complete transforms with `setPosition([x, y, z])`, `setRotor([x, y, z, w])`, and `setScale([x, y, z])`. `translate(...)`, `rotate(...)`, and `rotateX/Y/Z(...)` are convenience methods over those same SAB lanes. The camera helpers use this same pattern; see [Cameras and controls](/guide/cameras).
 
 <Playground example="sab" />
 

docs/index.md

@@ -39,7 +39,7 @@ const mesh = new Mesh(scene, {
 });
 await mesh.ready;
 
-mesh.position[0] = 0.25; // direct SAB mutation
+mesh.position.x = 0.25; // direct SAB mutation
 ```
 
 `Scene` installs one HDR clustered-forward loadout. Adding compute, custom shaders, textures, or post effects rebuilds that same loadout; changing values already present in shared rows does not send a message.