почему размер точек в объекте points одинаковый, хотя должен быть разный у каждой точки?
не переписывай весь код, только там, где нужно поправить

import * as THREE from 'three';
import { GLTFLoader } from 'three/examples/jsm/loaders/GLTFLoader';
import { OrbitControls } from 'three/examples/jsm/controls/OrbitControls'

const scene = new THREE.Scene();
const camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);
camera.position.z = 5;

const renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);

const controls = new OrbitControls( camera, renderer.domElement );
controls.enableZoom = false;

controls.enableDamping = true; 
controls.dampingFactor = 0.05; 

const shaderCode = document.getElementById("fragShader").innerHTML;
THREE.ImageUtils.crossOrigin = '';
const texture = new THREE.TextureLoader().load('gradient-2.png');



const loader = new GLTFLoader();
const url = 'GRAF_3_23.glb';

loader.load(url, function (gltf) {
  const model = gltf.scene;
  
  model.traverse((child) => {
    if (child.isMesh) {
      const geometry = child.geometry;

      const texturePoint = new THREE.TextureLoader().load('texture3.png');
      
      const sizeVariation = 1.1;

      const geometryPoint = new THREE.BufferGeometry();

      const positions = geometry.getAttribute('position').array;


      
      const materialPoint = new THREE.PointsMaterial({
        sizeAttenuation: false,
        map: texturePoint,
        alphaTest: 0.01,
        transparent: true,
        color: new THREE.Color(1., 1., 1.),
        opacity: 1.
      });
      const sizes = new Float32Array(positions.length / 3);
      for (let i = 0; i < sizes.length; i++) {
        sizes[i] = 0.01 + Math.random() * 0.04; // каждый размер будет случайным числом от 0 до 1
      }
      
      const randomPosition = [];
      for (let i = 0; i < positions.length; i += 3) {
        randomPosition.push(10.0*Math.random()-5.0, 10.0*Math.random()-5.0, 10.0*Math.random()-5.0);
      }
      const randomPositionCopy = [...randomPosition];
      
      let increment = 0.002;
      
      geometryPoint.setAttribute('position', new THREE.Float32BufferAttribute(positions, 3));
      
      const points = new THREE.Points(geometryPoint, materialPoint);
      const geometryPoints = points.geometry; 
      geometryPoint.setAttribute('size', new THREE.BufferAttribute(sizes, 1));
      const sizesPoints = geometryPoints.attributes.size.array;
      for (let i = 0; i < sizesPoints.length; i++) {
        console.log('Размер точки', i, ':', sizesPoints[i]);
      }
      geometryPoint.setAttribute('size', new THREE.BufferAttribute(sizes, 1));

      geometry.setAttribute('position', new THREE.BufferAttribute(new Float32Array(randomPosition), 3));
      function updateArray(increment) {
        for(let j = 0; j < 75; j++) {
          for(let i = 0; i<randomPosition.length; i++) {
            if (randomPosition[i] < positions[i]) {
              randomPosition[i] = randomPosition[i] + increment;
            } else if(randomPosition[i] > positions[i]) {
              randomPosition[i] = randomPosition[i] - increment;
            } else if((randomPosition[i] - positions[i]) < 0.002) {
              randomPosition[i] = positions[i];
            }
          }
        }
        geometryPoint.setAttribute('position', new THREE.BufferAttribute(new Float32Array(randomPosition), 3));
      }
      function reverseUpdateArray(increment) {
        for(let j = 0; j < 75; j++) {
          for(let i = 0; i<randomPosition.length; i++) {
            if (randomPosition[i] < randomPositionCopy[i]) {
              randomPosition[i] = randomPosition[i] + increment;
            } else if(randomPosition[i] > randomPositionCopy[i]) {
              randomPosition[i] = randomPosition[i] - increment;
            } else if((randomPosition[i] - randomPositionCopy[i]) < 0.002) {
              randomPosition[i] = randomPositionCopy[i];
            }
          }
        }
        geometryPoint.setAttribute('position', new THREE.BufferAttribute(new Float32Array(randomPosition), 3));
      }

      let time = 0;
      let sinPosition;
      let sinPosition2;
      let cosPosition;
      let randSignArray = [];
      let sign;
      let ratio = 1.0;

      for(let i = 0; i<randomPosition.length; i++) {
        sign = Math.random() < 0.5 ? -1.0 : 1.0;
        randSignArray[i] = sign;
      }
      geometryPoint.setAttribute('position', new THREE.BufferAttribute(new Float32Array(randomPosition), 3));
      window.addEventListener('wheel', function(event) {
        if (event.deltaY > 0) {
          updateArray(increment);
          if(ratio > 0.0) {
            ratio -= 0.01;
          }
        } else {
          reverseUpdateArray(increment);
          ratio += 0.01;
        }

      });


      scene.add(points);
      points.rotateX(Math.PI/2.0);
    }
  });
  camera.position.z = 3;



// ________________________________________________________________________________________________________________________________________________

    // Создаем переменные для точки и радиуса
  let point = new THREE.Vector3(0, 0, 0);
  let radius = 1;

  // Создаем функцию для генерации случайной точки внутри заданного радиуса
  function generateRandomPointInRadius(radius) {
    let angle1 = Math.random() * 2 * Math.PI;
    let angle2 = Math.random() * 2 * Math.PI;
    let x = radius * Math.sin(angle1) * Math.cos(angle2);
    let y = radius * Math.sin(angle1) * Math.sin(angle2);
    let z = radius * Math.cos(angle1);
    return new THREE.Vector3(x, y, z);
  }

  // Инициализируем переменные для генерации случайной точки
  let randomPoint = generateRandomPointInRadius(radius);
  let dist = point.distanceTo(randomPoint);
  let t = 0;

  // Создаем функцию для анимации точки
  function animatePoint() {
    t += 0.01;
    if (t > 1) {
      randomPoint = generateRandomPointInRadius(radius);
      dist = point.distanceTo(randomPoint);
      t = 0;
    }
    let newPos = point.clone().lerp(randomPoint, t);
    let moveDist = newPos.distanceTo(point);
    if (moveDist >= dist) {
      randomPoint = generateRandomPointInRadius(radius);
      dist = point.distanceTo(randomPoint);
      t = 0;
    }
    point.copy(newPos);
  }

  // Добавляем точку на сцену
  let pointGeometry = new THREE.SphereGeometry(0.2, 32, 32);
  let pointMaterial = new THREE.MeshBasicMaterial({color: 0xff0000});
  let pointMesh = new THREE.Mesh(pointGeometry, pointMaterial);
  pointMesh.position.set(point.x, point.y, point.z);
  // scene.add(pointMesh);


// ________________________________________________________________________________________________________________________________________________



  let uniforms = {
    mouseCoord: {type:'v3', value: new THREE.Vector3()},
    tex: { type:'t', value:texture },
    res: { type:'v2', value:new THREE.Vector2(window.innerWidth,window.innerHeight)}
  };

  const planeGeometry = new THREE.PlaneGeometry(1000, 1000);
  const planeMaterial = new THREE.ShaderMaterial({
    uniforms:uniforms, 
    fragmentShader:shaderCode,
    side: THREE.DoubleSide
  });
  const planeMesh = new THREE.Mesh(planeGeometry, planeMaterial);
  scene.add(planeMesh);
  planeMesh.position.set(0, 0, -85);


  // controls.addEventListener('change', function() {
  //   planeMesh.rotation.copy(camera.rotation);
  // });

  const group = new THREE.Group(); // создаем новую группу
  group.add(planeMesh); // добавляем куб в группу
  scene.add(group);

  let targetX = 0;
  let targetY = 0;
  let currentX = 0;
  let currentY = 0;

  function update() {
      requestAnimationFrame(update);
      const diffX = targetX - currentX;
      const diffY = targetY - currentY;
      const distance = Math.sqrt(diffX * diffX + diffY * diffY);
      const speed = distance / 10;
      if (distance < 1.0) {
          currentX = targetX;
          currentY = targetY;
      } else {
          currentX += speed * diffX / distance;
          currentY += speed * diffY / distance;
      }
  }
  update();

  document.addEventListener('mousemove', (event) => {
    targetX = event.clientX;
    targetY = event.clientY;
    uniforms.mouseCoord.value.x = currentX;
    uniforms.mouseCoord.value.y = -currentY + window.innerHeight;
  });


  group.position.set(camera.position.x, camera.position.y, camera.position.z);
  function animate() {
    requestAnimationFrame(animate);
    animatePoint();
    group.rotation.x = camera.rotation.x;
    group.rotation.y = camera.rotation.y;
    group.rotation.z = camera.rotation.z;
    controls.update();
    uniforms.mouseCoord.value.x = currentX;
    uniforms.mouseCoord.value.y = -currentY + window.innerHeight;
    renderer.render(scene, camera);
  }
  animate();
});