three.js实现电子围栏效果（纹理贴图）

实现步骤

1. 围栏的坐标
2. 坐标转换为几何体顶点，uv顶点坐标
3. 加载贴图，移动

图例

代码

<template>
  <div class="app">
    <div ref="canvesRef" class="canvas-wrap"></div>
  </div>
</template>

<script setup>
import { ref, onMounted } from "vue";
import * as THREE from "three";
import { OrbitControls } from "three/addons/controls/OrbitControls.js";

const canvesRef = ref(null);
const canvasWidth = window.innerWidth;
const canvasHeight = window.innerHeight;
let scene;
let camera;
let renderer;
let axesHelper;
let cameraControls;

init();
render();
function init() {
  // 场景
  scene = new THREE.Scene();
  // 模型
  addModel();
  // 相机
  camera = new THREE.PerspectiveCamera(
    75,
    canvasWidth / canvasHeight,
    0.1,
    3000
  );
  camera.position.set(300, 300, 300);
  // camera.lookAt(0, 0, 0);
  // 坐标辅助对象
  axesHelper = new THREE.AxesHelper(200);
  scene.add(axesHelper);

  // 渲染器
  //antialias - 是否执行抗锯齿。默认为false.
  renderer = new THREE.WebGLRenderer();
  renderer.setSize(canvasWidth, canvasHeight);
  // 相机轨道控制器
  cameraControls = new OrbitControls(camera, renderer.domElement);
}
function addModel() {
  // 坐标
  const points = [
    [0, 0, 0],
    [0, 0, 200],
    [200, 0, 200],
    [200, 0, 0],
    [0, 0, 0],
  ];
  const height = 30; // 高度
  const color1 = "#ff00ff"; // 颜色
  // 围栏距离 累加
  const pointDistance = [];
  // 围栏总长度
  const distance = points.reduce((totalDistance, point, index) => {
    let segmentDistance = 0;
    if (index > 0) {
      let lastPoint = new THREE.Vector3(...points[index - 1]);
      let currPoint = new THREE.Vector3(...point);
      segmentDistance = lastPoint.distanceTo(currPoint);
    }
    totalDistance += segmentDistance;
    pointDistance.push(totalDistance);
    return totalDistance;
  }, 0);

  // console.log(distance, pointDistance);

  // 几何体
  const geometry = new THREE.BufferGeometry(); // 缓冲几何体
  const posArr = [];
  const uvArr = [];
  // 遍历坐标
  // posArr 几何体顶点
  points.forEach((point, index) => {
    if (index == 0) return;
    const lastPoint = points[index - 1];

    // 三角面1
    posArr.push(...lastPoint);
    uvArr.push(pointDistance[index - 1] / distance, 0);
    posArr.push(...point);
    uvArr.push(pointDistance[index] / distance, 0);
    posArr.push(lastPoint[0], lastPoint[1] + height, lastPoint[2]);
    uvArr.push(pointDistance[index - 1] / distance, 1);

    // 三角面2
    posArr.push(...point);
    uvArr.push(pointDistance[index] / distance, 0);
    posArr.push(point[0], point[1] + height, point[2]);
    uvArr.push(pointDistance[index] / distance, 1);
    posArr.push(lastPoint[0], lastPoint[1] + height, lastPoint[2]);
    uvArr.push(pointDistance[index - 1] / distance, 1);
  });
  console.log(posArr, uvArr);
  geometry.setAttribute(
    "position",
    new THREE.BufferAttribute(new Float32Array(posArr), 3)
  );
  geometry.setAttribute(
    "uv",
    new THREE.BufferAttribute(new Float32Array(uvArr), 2)
  );
  // 纹理
  const texture = new THREE.TextureLoader().load("../src/assets/img/icon.png");
  texture.wrapS = THREE.RepeatWrapping;
  texture.wrapT = THREE.RepeatWrapping;
  // 材质
  const material = new THREE.MeshBasicMaterial({
    // color: color1,
    map: texture,
    transparent: true,
    opacity: 1,
    depthWrite: false,
    side: THREE.DoubleSide,
  });
  // 创建围栏
  const mesh = new THREE.Mesh(geometry, material);
  scene.add(mesh);
  texture.repeat.set(10, 1); // 平铺

  textrue_offset(texture, "top", 5);
}
function textrue_offset(texture, direction = "right", speed = 0.5) {
  // 开始时间
  const start = Date.now();
  const h = () => {
    requestAnimationFrame(h);
    const now = Date.now();
    const offset = ((now - start) / 1000) * speed;
    switch (direction) {
      case "left":
        texture.offset = new THREE.Vector2(offset, 0); //纹理偏移
        break;
      case "right":
        texture.offset = new THREE.Vector2(-offset, 0);
        break;
      case "top":
        texture.offset = new THREE.Vector2(0, -offset);
        break;
      case "left":
        texture.offset = new THREE.Vector2(0, offset);
        break;
    }
  };
  h();
}
function render() {
  renderer.render(scene, camera);
  requestAnimationFrame(render);
}
onMounted(() => {
  canvesRef.value.appendChild(renderer.domElement);
});
</script>

<style lang="scss" scoped>
.app {
  position: relative;
}
</style>