webgl_decals

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";
import { OrbitControls } from "three/examples/jsm/controls/OrbitControls.js";
import { GLTFLoader } from "three/examples/jsm/loaders/GLTFLoader.js";
import { DecalGeometry } from "three/examples/jsm/geometries/DecalGeometry.js";

/** @type {import("@minisheeep/mp-three-examples").OfficialExampleInfo} */
const exampleInfo = {
  name: "webgl_decals",
  useLoaders: [GLTFLoader],
  info: [
    [
      { tag: "a", link: "https://threejs.org", content: "three.js" },
      { tag: "text", content: "- decal splatter" }
    ],
    [{ tag: "text", content: "click to shoot" }]
  ],
  init: ({ window, canvas, GUI, Stats, needToDispose, useFrame }) => {
    let renderer, scene, camera, stats;
    let mesh;
    let raycaster;
    let line;
    const intersection = {
      intersects: false,
      point: new THREE.Vector3(),
      normal: new THREE.Vector3()
    };
    const mouse = new THREE.Vector2();
    const intersects = [];
    const textureLoader = new THREE.TextureLoader();
    const decalDiffuse = textureLoader.load("textures/decal/decal-diffuse.png");
    decalDiffuse.colorSpace = THREE.SRGBColorSpace;
    const decalNormal = textureLoader.load("textures/decal/decal-normal.jpg");
    const decalMaterial = new THREE.MeshPhongMaterial({
      specular: 4473924,
      map: decalDiffuse,
      normalMap: decalNormal,
      normalScale: new THREE.Vector2(1, 1),
      shininess: 30,
      transparent: true,
      depthTest: true,
      depthWrite: false,
      polygonOffset: true,
      polygonOffsetFactor: -4,
      wireframe: false
    });
    const decals = [];
    let mouseHelper;
    const position = new THREE.Vector3();
    const orientation = new THREE.Euler();
    const size = new THREE.Vector3(10, 10, 10);
    const params = {
      minScale: 10,
      maxScale: 20,
      rotate: true,
      clear: function() {
        removeDecals();
      }
    };
    init();
    function init() {
      renderer = new THREE.WebGLRenderer({ antialias: true, canvas });
      renderer.setPixelRatio(window.devicePixelRatio);
      renderer.setSize(window.innerWidth, window.innerHeight);
      renderer.setAnimationLoop(animate);
      stats = new Stats(renderer);
      scene = new THREE.Scene();
      camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 1, 1e3);
      camera.position.z = 120;
      const controls = new OrbitControls(camera, renderer.domElement);
      controls.minDistance = 50;
      controls.maxDistance = 200;
      scene.add(new THREE.AmbientLight(6710886));
      const dirLight1 = new THREE.DirectionalLight(16768460, 3);
      dirLight1.position.set(1, 0.75, 0.5);
      scene.add(dirLight1);
      const dirLight2 = new THREE.DirectionalLight(13421823, 3);
      dirLight2.position.set(-1, 0.75, -0.5);
      scene.add(dirLight2);
      const geometry = new THREE.BufferGeometry();
      geometry.setFromPoints([new THREE.Vector3(), new THREE.Vector3()]);
      line = new THREE.Line(geometry, new THREE.LineBasicMaterial());
      scene.add(line);
      loadLeePerrySmith();
      raycaster = new THREE.Raycaster();
      mouseHelper = new THREE.Mesh(new THREE.BoxGeometry(1, 1, 10), new THREE.MeshNormalMaterial());
      mouseHelper.visible = false;
      scene.add(mouseHelper);
      window.addEventListener("resize", onWindowResize);
      let moved = false;
      controls.addEventListener("change", function() {
        moved = true;
      });
      canvas.addEventListener("pointerdown", function() {
        moved = false;
      });
      canvas.addEventListener("pointerup", function(event) {
        if (moved === false) {
          checkIntersection(event.clientX, event.clientY);
          if (intersection.intersects) shoot();
        }
      });
      canvas.addEventListener("pointermove", onPointerMove);
      function onPointerMove(event) {
        if (event.isPrimary) {
          checkIntersection(event.clientX, event.clientY);
        }
      }
      function checkIntersection(x, y) {
        if (mesh === void 0) return;
        mouse.x = x / window.innerWidth * 2 - 1;
        mouse.y = -(y / window.innerHeight) * 2 + 1;
        raycaster.setFromCamera(mouse, camera);
        raycaster.intersectObject(mesh, false, intersects);
        if (intersects.length > 0) {
          const p = intersects[0].point;
          mouseHelper.position.copy(p);
          intersection.point.copy(p);
          const n = intersects[0].face.normal.clone();
          n.transformDirection(mesh.matrixWorld);
          n.multiplyScalar(10);
          n.add(intersects[0].point);
          intersection.normal.copy(intersects[0].face.normal);
          mouseHelper.lookAt(n);
          const positions = line.geometry.attributes.position;
          positions.setXYZ(0, p.x, p.y, p.z);
          positions.setXYZ(1, n.x, n.y, n.z);
          positions.needsUpdate = true;
          intersection.intersects = true;
          intersects.length = 0;
        } else {
          intersection.intersects = false;
        }
      }
      const gui = new GUI();
      gui.add(params, "minScale", 1, 30);
      gui.add(params, "maxScale", 1, 30);
      gui.add(params, "rotate");
      gui.add(params, "clear");
      gui.open();
      needToDispose(renderer, scene, controls);
    }
    function loadLeePerrySmith() {
      const map = textureLoader.load("models/gltf/LeePerrySmith/Map-COL.jpg");
      map.colorSpace = THREE.SRGBColorSpace;
      const specularMap = textureLoader.load("models/gltf/LeePerrySmith/Map-SPEC.jpg");
      const normalMap = textureLoader.load(
        "models/gltf/LeePerrySmith/Infinite-Level_02_Tangent_SmoothUV.jpg"
      );
      const loader = new GLTFLoader();
      loader.load("models/gltf/LeePerrySmith/LeePerrySmith.glb", function(gltf) {
        mesh = gltf.scene.children[0];
        mesh.material = new THREE.MeshPhongMaterial({
          specular: 1118481,
          map,
          specularMap,
          normalMap,
          shininess: 25
        });
        scene.add(mesh);
        mesh.scale.set(10, 10, 10);
      });
    }
    function shoot() {
      position.copy(intersection.point);
      orientation.copy(mouseHelper.rotation);
      if (params.rotate) orientation.z = Math.random() * 2 * Math.PI;
      const scale = params.minScale + Math.random() * (params.maxScale - params.minScale);
      size.set(scale, scale, scale);
      const material = decalMaterial.clone();
      material.color.setHex(Math.random() * 16777215);
      const m = new THREE.Mesh(new DecalGeometry(mesh, position, orientation, size), material);
      m.renderOrder = decals.length;
      decals.push(m);
      scene.add(m);
    }
    function removeDecals() {
      decals.forEach(function(d) {
        scene.remove(d);
      });
      decals.length = 0;
    }
    function onWindowResize() {
      camera.aspect = window.innerWidth / window.innerHeight;
      camera.updateProjectionMatrix();
      renderer.setSize(window.innerWidth, window.innerHeight);
    }
    function animate() {
      renderer.render(scene, camera);
      stats.update();
    }
  }
};
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;