使用 Three.js 实现网格光斑扩散效果，具体要求：

【核心特效】
- 点阵上的圆形/横向扩散光环
- 网格线与加号标记组合背景
- GSAP 驱动的相机动画

【场景与光照】
- 深蓝色雾效背景
- 海洋纹理地面
- 纯视觉效果，无需光源

【交互与控制】
- OrbitControls 视角控制
- 自动循环动画
- 响应式窗口适配

【技术要求】
- Three.js 最新版本
- GSAP 动画库
- PointsMaterial + onBeforeCompile 着色器扩展

const rows = opt.pointLayout.row, cols = opt.pointLayout.col;
const posArr = new Float32Array(rows * cols * 3);
for (let i = 0; i < rows * cols; i++) {
  const r = i % rows, c = Math.floor(i / rows);
  posArr[i * 3]     = (r / (rows - 1)) * opt.gridSize - opt.gridSize / 2;
  posArr[i * 3 + 1] = 0;
  posArr[i * 3 + 2] = (c / (cols - 1)) * opt.gridSize - opt.gridSize / 2;
}
const pointGeo = new THREE.BufferGeometry();
pointGeo.setAttribute('position', new THREE.BufferAttribute(posArr, 3));

uniform float uTime, uSpeed, uWidth, uDir;
uniform vec3 uColor;

void main() {
  float radius = uTime * uSpeed;
  float width  = min(uWidth, uTime * 5.0);
  vec2  center = vec2(0.0);
  float dist   = uDir == 1.0 ? abs(vPos.x) : distance(vPos.xz, center);

  if (dist > radius && dist < radius + 2.0 * width) {
    float pct = dist < radius + width
      ? (dist - radius) / width
      : (dist - radius - width) / width;
    vec3 outCol = dist < radius + width
      ? mix(outgoingLight, uColor, pct)
      : mix(uColor, outgoingLight, pct);
    gl_FragColor = vec4(outCol, diffuseColor.a);
  } else {
    gl_FragColor = vec4(outgoingLight, diffuseColor.a);
  }
}

const plusGeoArr = [];
for (let r = 0; r <= opt.gridDivision; r++) {
  for (let c = 0; c <= opt.gridDivision; c++) {
    const shape = new THREE.Shape([
      new THREE.Vector2(-armLen, -lineW), new THREE.Vector2(-lineW, -lineW),
      new THREE.Vector2(-lineW, -armLen), new THREE.Vector2(lineW, -armLen),
      new THREE.Vector2(lineW, -lineW),   new THREE.Vector2(armLen, -lineW),
      new THREE.Vector2(armLen, lineW),   new THREE.Vector2(lineW, lineW),
      new THREE.Vector2(lineW, armLen),   new THREE.Vector2(-lineW, armLen),
      new THREE.Vector2(-lineW, lineW),   new THREE.Vector2(-armLen, lineW)
    ]);
    plusGeoArr.push(
      new THREE.ShapeGeometry(shape).translate(-half + r * cellSize, -half + c * cellSize, 0)
    );
  }
}
const plusMesh = new THREE.Mesh(mergeGeometries(plusGeoArr), ...);

gsap.timeline()
  .to(camera.position, { duration: 2.5, x: -20.46, y: 19.30, z: 58.38, ease: 'circ.out' })
  .to(camera.position, { duration: 2.5, x: -0.25,  y: 12.40, z: 14.65, ease: 'circ.out' });