webgl_interactive_raycasting_points

对应 three.js 示例地址 。

仅需关注 init 函数的内容，其他部分都是示例小程序所使用的描述配置。

example.js

import * as THREE from "three";

/** @type {import("@minisheeep/mp-three-examples").OfficialExampleInfo} */
const exampleInfo = {
  name: "webgl_interactive_raycasting_points",
  useLoaders: [],
  info: [
    [
      {
        tag: "a",
        link: "https://threejs.org",
        content: "three.js"
      },
      {
        tag: "text",
        content: "webgl - interactive - raycasting - points"
      }
    ]
  ],
  init: ({ window, canvas, GUI, Stats, needToDispose, useFrame }) => {
    let renderer, scene, camera, stats;
    let pointclouds;
    let raycaster;
    let intersection = null;
    let spheresIndex = 0;
    let clock;
    let toggle = 0;
    const pointer = new THREE.Vector2();
    const spheres = [];
    const threshold = 0.1;
    const pointSize = 0.05;
    const width = 80;
    const length = 160;
    const rotateY = new THREE.Matrix4().makeRotationY(5e-3);
    init();
    function generatePointCloudGeometry(color, width2, length2) {
      const geometry = new THREE.BufferGeometry();
      const numPoints = width2 * length2;
      const positions = new Float32Array(numPoints * 3);
      const colors = new Float32Array(numPoints * 3);
      let k = 0;
      for (let i = 0; i < width2; i++) {
        for (let j = 0; j < length2; j++) {
          const u = i / width2;
          const v = j / length2;
          const x = u - 0.5;
          const y = (Math.cos(u * Math.PI * 4) + Math.sin(v * Math.PI * 8)) / 20;
          const z = v - 0.5;
          positions[3 * k] = x;
          positions[3 * k + 1] = y;
          positions[3 * k + 2] = z;
          const intensity = (y + 0.1) * 5;
          colors[3 * k] = color.r * intensity;
          colors[3 * k + 1] = color.g * intensity;
          colors[3 * k + 2] = color.b * intensity;
          k++;
        }
      }
      geometry.setAttribute("position", new THREE.BufferAttribute(positions, 3));
      geometry.setAttribute("color", new THREE.BufferAttribute(colors, 3));
      geometry.computeBoundingBox();
      return geometry;
    }
    function generatePointcloud(color, width2, length2) {
      const geometry = generatePointCloudGeometry(color, width2, length2);
      const material = new THREE.PointsMaterial({ size: pointSize, vertexColors: true });
      return new THREE.Points(geometry, material);
    }
    function generateIndexedPointcloud(color, width2, length2) {
      const geometry = generatePointCloudGeometry(color, width2, length2);
      const numPoints = width2 * length2;
      const indices = new Uint16Array(numPoints);
      let k = 0;
      for (let i = 0; i < width2; i++) {
        for (let j = 0; j < length2; j++) {
          indices[k] = k;
          k++;
        }
      }
      geometry.setIndex(new THREE.BufferAttribute(indices, 1));
      const material = new THREE.PointsMaterial({ size: pointSize, vertexColors: true });
      return new THREE.Points(geometry, material);
    }
    function generateIndexedWithOffsetPointcloud(color, width2, length2) {
      const geometry = generatePointCloudGeometry(color, width2, length2);
      const numPoints = width2 * length2;
      const indices = new Uint16Array(numPoints);
      let k = 0;
      for (let i = 0; i < width2; i++) {
        for (let j = 0; j < length2; j++) {
          indices[k] = k;
          k++;
        }
      }
      geometry.setIndex(new THREE.BufferAttribute(indices, 1));
      geometry.addGroup(0, indices.length);
      const material = new THREE.PointsMaterial({ size: pointSize, vertexColors: true });
      return new THREE.Points(geometry, material);
    }
    function init() {
      scene = new THREE.Scene();
      clock = new THREE.Clock();
      camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 1, 1e4);
      camera.position.set(10, 10, 10);
      camera.lookAt(scene.position);
      camera.updateMatrix();
      const pcBuffer = generatePointcloud(new THREE.Color(1, 0, 0), width, length);
      pcBuffer.scale.set(5, 10, 10);
      pcBuffer.position.set(-5, 0, 0);
      scene.add(pcBuffer);
      const pcIndexed = generateIndexedPointcloud(new THREE.Color(0, 1, 0), width, length);
      pcIndexed.scale.set(5, 10, 10);
      pcIndexed.position.set(0, 0, 0);
      scene.add(pcIndexed);
      const pcIndexedOffset = generateIndexedWithOffsetPointcloud(
        new THREE.Color(0, 1, 1),
        width,
        length
      );
      pcIndexedOffset.scale.set(5, 10, 10);
      pcIndexedOffset.position.set(5, 0, 0);
      scene.add(pcIndexedOffset);
      pointclouds = [pcBuffer, pcIndexed, pcIndexedOffset];
      const sphereGeometry = new THREE.SphereGeometry(0.1, 32, 32);
      const sphereMaterial = new THREE.MeshBasicMaterial({ color: 16711680 });
      for (let i = 0; i < 40; i++) {
        const sphere = new THREE.Mesh(sphereGeometry, sphereMaterial);
        scene.add(sphere);
        spheres.push(sphere);
      }
      renderer = new THREE.WebGLRenderer({ antialias: true, canvas });
      renderer.setPixelRatio(window.devicePixelRatio);
      renderer.setSize(window.innerWidth, window.innerHeight);
      renderer.setAnimationLoop(animate);
      raycaster = new THREE.Raycaster();
      raycaster.params.Points.threshold = threshold;
      stats = new Stats(renderer);
      window.addEventListener("resize", onWindowResize);
      canvas.addEventListener("pointermove", onPointerMove);
      needToDispose(renderer, scene);
    }
    function onPointerMove(event) {
      pointer.x = event.clientX / window.innerWidth * 2 - 1;
      pointer.y = -(event.clientY / window.innerHeight) * 2 + 1;
    }
    function onWindowResize() {
      camera.aspect = window.innerWidth / window.innerHeight;
      camera.updateProjectionMatrix();
      renderer.setSize(window.innerWidth, window.innerHeight);
    }
    function animate() {
      render();
      stats.update();
    }
    function render() {
      camera.applyMatrix4(rotateY);
      camera.updateMatrixWorld();
      raycaster.setFromCamera(pointer, camera);
      const intersections = raycaster.intersectObjects(pointclouds, false);
      intersection = intersections.length > 0 ? intersections[0] : null;
      if (toggle > 0.02 && intersection !== null) {
        spheres[spheresIndex].position.copy(intersection.point);
        spheres[spheresIndex].scale.set(1, 1, 1);
        spheresIndex = (spheresIndex + 1) % spheres.length;
        toggle = 0;
      }
      for (let i = 0; i < spheres.length; i++) {
        const sphere = spheres[i];
        sphere.scale.multiplyScalar(0.98);
        sphere.scale.clampScalar(0.01, 1);
      }
      toggle += clock.getDelta();
      renderer.render(scene, camera);
    }
  }
};
export {
  exampleInfo as default
};

typings.d.ts

import { Loader, TypedArray } from 'three';
/**
 * 官网示例的多端使用封装把版本
 * */
export interface OfficialExampleInfo extends MiniProgramMeta {
  /*** 示例名称（保持和官网一致）*/
  name: string;
  /** main */
  init: (context: LoadContext) => void;
}

export interface LoadContext {
  //为了减少官方代码的改动，实际上等同于 canvas
  window: EventTarget & { innerWidth: number; innerHeight: number; devicePixelRatio: number };
  /** HTMLCanvasElement */
  canvas: any;
  /** https://www.npmjs.com/package/lil-gui */
  GUI: any;
  /**
   * https://www.npmjs.com/package/stats.js
   * 也可以使用其他受支持的版本
   * */
  Stats: any;
  /** 收集需要 dispose 的对象（官方示例没有处理这部分）*/
  needToDispose: (...objs: any[]) => void | ((fromFn: () => any[]) => void);

  /**基于 raq 的通用封装 */
  useFrame(animateFunc: (/** ms */ delta: number) => void): { cancel: () => void };

  /** 显示加载模态框 */
  requestLoading(text?: string): Promise<void>;

  /** 隐藏加载模态框*/
  cancelLoading(): void;

  /** 保存文件的通用封装*/
  saveFile(
    fileName: string,
    data: ArrayBuffer | TypedArray | DataView | string
  ): Promise<string | null>;

  /** 示例使用 DracoDecoder 时的资源路径 */
  DecoderPath: {
    GLTF: string;
    STANDARD: string;
  };

  /** 为资源路径拼上 CDN 前缀 */
  withCDNPrefix(path: string): string;

  /**
   * 在小程序中应使用 import { VideoTexture } from '@minisheep/three-platform-adapter/override/jsm/textures/VideoTexture.js';
   * 正常情况（web） 可直接使用 THREE.VideoTexture
   * */
  getVideoTexture(videoOptions: VideoOptions): Promise<[{ isVideoTexture: true }, video: any]>;

  /**
   * 在小程序中应使用 import { CameraTexture } from '@minisheep/three-platform-adapter/override/jsm/textures/CameraTexture.js';
   * 正常情况（web） 可参考示例 webgl_materials_video_webcam
   * */
  getCameraTexture(): { isVideoTexture: true };

  /** 用于动态修改 info 中的占位符*/
  bindInfoText(template: `$${string}$`, initValue?: string): { value: string };

  /** 分屏控件对应的事件回调 */
  onSlideStart(handle: () => void): void;
  /** 分屏控件对应的事件回调 */
  onSlideEnd(handle: () => void): void;
  /** 分屏控件对应的事件回调 */
  onSlideChange(handle: (offset: number, boxSize: number) => void): void;
}

export type VideoOptions = {
  src: string;
  /** 相当于 HTMLVideoElement 的 naturalWidth (小程序中获取不到)*/
  width: number;
  /** 相当于 HTMLVideoElement 的 naturalHeight (小程序中获取不到)*/
  height: number;
  loop?: boolean;
  autoplay?: boolean;
  muted?: boolean;
};

/** 示例小程序中使用的一些配置 */
export interface MiniProgramMeta {
  /** 用于统计加载相关信息 */
  useLoaders: Loader[];
  /** 通用 info */
  info: TagItem[][];
  /** 特殊 info */
  infoPanel?: {
    left?: [string, string][];
    right?: [string, string][];
  };
  /** 分屏控件配置 */
  needSlider?: {
    /** 方向 */
    direction?: 'horizontal' | 'vertical';
    /** 初始偏移 0-100 */
    initPosition?: number;
  };
  /** 操作摇杆控件 */
  needArrowControls?: boolean;
  /** 默认需要的画布类型 */
  canvasType?: '2d' | 'webgl' | 'webgl2';
  /** 为保持效果一致所需要的画布样式 */
  canvasStyle?: {
    bgColor?: string;
    width?: number | string;
    height?: number | string;
  };
  /** 部分示例需要在加载前进行一些提示 */
  initAfterConfirm?: {
    /**
     * 提示类型
     * @default 'default'
     * */
    type?: 'warning' | 'default';
    text: string[];
  };
}

export interface BaseTag<T extends string> {
  tag: T;
  content: string;
}

export interface ATag extends BaseTag<'a'> {
  link: string;
}

export type TextTag = BaseTag<'text'>;

export type TagItem = TextTag | ATag;