webgl_instancing_scatter
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。
js
import * as THREE from "three";
import { MeshSurfaceSampler } from "three/examples/jsm/math/MeshSurfaceSampler.js";
import { GLTFLoader } from "three/examples/jsm/loaders/GLTFLoader.js";
/** @type {import("@minisheeep/mp-three-examples").OfficialExampleInfo} */
const exampleInfo = {
name: "webgl_instancing_scatter",
useLoaders: [GLTFLoader],
info: [],
init: ({ window, canvas, GUI, Stats, needToDispose, useFrame }) => {
let camera, scene, renderer, stats;
const api = {
count: 2e3,
distribution: "random",
resample,
surfaceColor: 16775044,
backgroundColor: 14914665
};
let stemMesh, blossomMesh;
let stemGeometry, blossomGeometry;
let stemMaterial, blossomMaterial;
let sampler;
const count = api.count;
const ages = new Float32Array(count);
const scales = new Float32Array(count);
const dummy = new THREE.Object3D();
const _position = new THREE.Vector3();
const _normal = new THREE.Vector3();
const _scale = new THREE.Vector3();
const surfaceGeometry = new THREE.TorusKnotGeometry(10, 3, 100, 16).toNonIndexed();
const surfaceMaterial = new THREE.MeshLambertMaterial({
color: api.surfaceColor,
wireframe: false
});
const surface = new THREE.Mesh(surfaceGeometry, surfaceMaterial);
const easeOutCubic = function(t) {
return --t * t * t + 1;
};
const scaleCurve = function(t) {
return Math.abs(easeOutCubic((t > 0.5 ? 1 - t : t) * 2));
};
const loader = new GLTFLoader();
loader.load("./models/gltf/Flower/Flower.glb", function(gltf) {
const _stemMesh = gltf.scene.getObjectByName("Stem");
const _blossomMesh = gltf.scene.getObjectByName("Blossom");
stemGeometry = _stemMesh.geometry.clone();
blossomGeometry = _blossomMesh.geometry.clone();
const defaultTransform = new THREE.Matrix4().makeRotationX(Math.PI).multiply(new THREE.Matrix4().makeScale(7, 7, 7));
stemGeometry.applyMatrix4(defaultTransform);
blossomGeometry.applyMatrix4(defaultTransform);
stemMaterial = _stemMesh.material;
blossomMaterial = _blossomMesh.material;
stemMesh = new THREE.InstancedMesh(stemGeometry, stemMaterial, count);
blossomMesh = new THREE.InstancedMesh(blossomGeometry, blossomMaterial, count);
const color = new THREE.Color();
const blossomPalette = [15861127, 15914105, 15911033, 15904887, 15877125];
for (let i = 0; i < count; i++) {
color.setHex(blossomPalette[Math.floor(Math.random() * blossomPalette.length)]);
blossomMesh.setColorAt(i, color);
}
stemMesh.instanceMatrix.setUsage(THREE.DynamicDrawUsage);
blossomMesh.instanceMatrix.setUsage(THREE.DynamicDrawUsage);
resample();
init();
});
function init() {
camera = new THREE.PerspectiveCamera(60, window.innerWidth / window.innerHeight, 0.1, 100);
camera.position.set(25, 25, 25);
camera.lookAt(0, 0, 0);
scene = new THREE.Scene();
scene.background = new THREE.Color(api.backgroundColor);
const pointLight = new THREE.PointLight(11176089, 2.5, 0, 0);
pointLight.position.set(50, -25, 75);
scene.add(pointLight);
scene.add(new THREE.AmbientLight(16777215, 3));
scene.add(stemMesh);
scene.add(blossomMesh);
scene.add(surface);
const gui = new GUI();
gui.add(api, "count", 0, count).onChange(function() {
stemMesh.count = api.count;
blossomMesh.count = api.count;
});
gui.add(api, "distribution").options(["random", "weighted"]).onChange(resample);
gui.add(api, "resample");
renderer = new THREE.WebGLRenderer({ antialias: true, canvas });
renderer.setPixelRatio(window.devicePixelRatio);
renderer.setSize(window.innerWidth, window.innerHeight);
renderer.setAnimationLoop(animate);
stats = new Stats(renderer);
window.addEventListener("resize", onWindowResize);
needToDispose(renderer, scene);
}
function resample() {
const vertexCount = surface.geometry.getAttribute("position").count;
console.info(
"Sampling " + count + " points from a surface with " + vertexCount + " vertices..."
);
console.time(".build()");
sampler = new MeshSurfaceSampler(surface).setWeightAttribute(api.distribution === "weighted" ? "uv" : null).build();
console.timeEnd(".build()");
console.time(".sample()");
for (let i = 0; i < count; i++) {
ages[i] = Math.random();
scales[i] = scaleCurve(ages[i]);
resampleParticle(i);
}
console.timeEnd(".sample()");
stemMesh.instanceMatrix.needsUpdate = true;
blossomMesh.instanceMatrix.needsUpdate = true;
}
function resampleParticle(i) {
sampler.sample(_position, _normal);
_normal.add(_position);
dummy.position.copy(_position);
dummy.scale.set(scales[i], scales[i], scales[i]);
dummy.lookAt(_normal);
dummy.updateMatrix();
stemMesh.setMatrixAt(i, dummy.matrix);
blossomMesh.setMatrixAt(i, dummy.matrix);
}
function updateParticle(i) {
ages[i] += 5e-3;
if (ages[i] >= 1) {
ages[i] = 1e-3;
scales[i] = scaleCurve(ages[i]);
resampleParticle(i);
return;
}
const prevScale = scales[i];
scales[i] = scaleCurve(ages[i]);
_scale.set(scales[i] / prevScale, scales[i] / prevScale, scales[i] / prevScale);
stemMesh.getMatrixAt(i, dummy.matrix);
dummy.matrix.scale(_scale);
stemMesh.setMatrixAt(i, dummy.matrix);
blossomMesh.setMatrixAt(i, dummy.matrix);
}
function onWindowResize() {
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
renderer.setSize(window.innerWidth, window.innerHeight);
}
function animate() {
render();
stats.update();
}
function render() {
if (stemMesh && blossomMesh) {
const time = Date.now() * 1e-3;
scene.rotation.x = Math.sin(time / 4);
scene.rotation.y = Math.sin(time / 2);
for (let i = 0; i < api.count; i++) {
updateParticle(i);
}
stemMesh.instanceMatrix.needsUpdate = true;
blossomMesh.instanceMatrix.needsUpdate = true;
stemMesh.computeBoundingSphere();
blossomMesh.computeBoundingSphere();
}
renderer.render(scene, camera);
}
}
};
export {
exampleInfo as default
};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;