webgl_gpgpu_birds
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 { GPUComputationRenderer } from "three/examples/jsm/misc/GPUComputationRenderer.js";
/** @type {import("@minisheeep/mp-three-examples").OfficialExampleInfo} */
const exampleInfo = {
name: "webgl_gpgpu_birds",
useLoaders: [],
info: [
[
{ tag: "a", link: "https://threejs.org", content: "three.js" },
{ tag: "text", content: "- webgl gpgpu birds" }
],
[{ tag: "text", content: "Move mouse to disturb birds." }]
],
init: ({ window, canvas, GUI, Stats, needToDispose, useFrame }) => {
const WIDTH = 32;
const BIRDS = WIDTH * WIDTH;
class BirdGeometry extends THREE.BufferGeometry {
constructor() {
super();
const trianglesPerBird = 3;
const triangles = BIRDS * trianglesPerBird;
const points = triangles * 3;
const vertices = new THREE.BufferAttribute(new Float32Array(points * 3), 3);
const birdColors = new THREE.BufferAttribute(new Float32Array(points * 3), 3);
const references = new THREE.BufferAttribute(new Float32Array(points * 2), 2);
const birdVertex = new THREE.BufferAttribute(new Float32Array(points), 1);
this.setAttribute("position", vertices);
this.setAttribute("birdColor", birdColors);
this.setAttribute("reference", references);
this.setAttribute("birdVertex", birdVertex);
let v = 0;
function verts_push() {
for (let i = 0; i < arguments.length; i++) {
vertices.array[v++] = arguments[i];
}
}
const wingsSpan = 20;
for (let f = 0; f < BIRDS; f++) {
verts_push(0, -0, -20, 0, 4, -20, 0, 0, 30);
verts_push(0, 0, -15, -20, 0, 0, 0, 0, 15);
verts_push(0, 0, 15, wingsSpan, 0, 0, 0, 0, -15);
}
for (let v2 = 0; v2 < triangles * 3; v2++) {
const triangleIndex = ~~(v2 / 3);
const birdIndex = ~~(triangleIndex / trianglesPerBird);
const x = birdIndex % WIDTH / WIDTH;
const y = ~~(birdIndex / WIDTH) / WIDTH;
const c = new THREE.Color(6710886 + ~~(v2 / 9) / BIRDS * 6710886);
birdColors.array[v2 * 3 + 0] = c.r;
birdColors.array[v2 * 3 + 1] = c.g;
birdColors.array[v2 * 3 + 2] = c.b;
references.array[v2 * 2] = x;
references.array[v2 * 2 + 1] = y;
birdVertex.array[v2] = v2 % 9;
}
this.scale(0.2, 0.2, 0.2);
}
}
let stats;
let camera, scene, renderer;
let mouseX = 0, mouseY = 0;
let windowHalfX = window.innerWidth / 2;
let windowHalfY = window.innerHeight / 2;
const BOUNDS = 800, BOUNDS_HALF = BOUNDS / 2;
let last = Date.now();
let gpuCompute;
let velocityVariable;
let positionVariable;
let positionUniforms;
let velocityUniforms;
let birdUniforms;
init();
function init() {
camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 1, 3e3);
camera.position.z = 350;
scene = new THREE.Scene();
scene.background = new THREE.Color(16777215);
scene.fog = new THREE.Fog(16777215, 100, 1e3);
renderer = new THREE.WebGLRenderer({ canvas });
renderer.setPixelRatio(window.devicePixelRatio);
renderer.setSize(window.innerWidth, window.innerHeight);
renderer.setAnimationLoop(animate);
initComputeRenderer();
stats = new Stats(renderer);
canvas.addEventListener("pointermove", onPointerMove);
window.addEventListener("resize", onWindowResize);
const gui = new GUI();
const effectController = {
separation: 20,
alignment: 20,
cohesion: 20,
freedom: 0.75
};
const valuesChanger = function() {
velocityUniforms["separationDistance"].value = effectController.separation;
velocityUniforms["alignmentDistance"].value = effectController.alignment;
velocityUniforms["cohesionDistance"].value = effectController.cohesion;
velocityUniforms["freedomFactor"].value = effectController.freedom;
};
valuesChanger();
gui.add(effectController, "separation", 0, 100, 1).onChange(valuesChanger);
gui.add(effectController, "alignment", 0, 100, 1e-3).onChange(valuesChanger);
gui.add(effectController, "cohesion", 0, 100, 0.025).onChange(valuesChanger);
gui.close();
initBirds();
needToDispose(renderer, scene);
}
function initComputeRenderer() {
gpuCompute = new GPUComputationRenderer(WIDTH, WIDTH, renderer);
const dtPosition = gpuCompute.createTexture();
const dtVelocity = gpuCompute.createTexture();
fillPositionTexture(dtPosition);
fillVelocityTexture(dtVelocity);
velocityVariable = gpuCompute.addVariable(
"textureVelocity",
`
uniform float time;
uniform float testing;
uniform float delta; // about 0.016
uniform float separationDistance; // 20
uniform float alignmentDistance; // 40
uniform float cohesionDistance; //
uniform float freedomFactor;
uniform vec3 predator;
const float width = resolution.x;
const float height = resolution.y;
const float PI = 3.141592653589793;
const float PI_2 = PI * 2.0;
// const float VISION = PI * 0.55;
float zoneRadius = 40.0;
float zoneRadiusSquared = 1600.0;
float separationThresh = 0.45;
float alignmentThresh = 0.65;
const float UPPER_BOUNDS = BOUNDS;
const float LOWER_BOUNDS = -UPPER_BOUNDS;
const float SPEED_LIMIT = 9.0;
float rand( vec2 co ){
return fract( sin( dot( co.xy, vec2(12.9898,78.233) ) ) * 43758.5453 );
}
void main() {
zoneRadius = separationDistance + alignmentDistance + cohesionDistance;
separationThresh = separationDistance / zoneRadius;
alignmentThresh = ( separationDistance + alignmentDistance ) / zoneRadius;
zoneRadiusSquared = zoneRadius * zoneRadius;
vec2 uv = gl_FragCoord.xy / resolution.xy;
vec3 birdPosition, birdVelocity;
vec3 selfPosition = texture2D( texturePosition, uv ).xyz;
vec3 selfVelocity = texture2D( textureVelocity, uv ).xyz;
float dist;
vec3 dir; // direction
float distSquared;
float separationSquared = separationDistance * separationDistance;
float cohesionSquared = cohesionDistance * cohesionDistance;
float f;
float percent;
vec3 velocity = selfVelocity;
float limit = SPEED_LIMIT;
dir = predator * UPPER_BOUNDS - selfPosition;
dir.z = 0.;
// dir.z *= 0.6;
dist = length( dir );
distSquared = dist * dist;
float preyRadius = 150.0;
float preyRadiusSq = preyRadius * preyRadius;
// move birds away from predator
if ( dist < preyRadius ) {
f = ( distSquared / preyRadiusSq - 1.0 ) * delta * 100.;
velocity += normalize( dir ) * f;
limit += 5.0;
}
// if (testing == 0.0) {}
// if ( rand( uv + time ) < freedomFactor ) {}
// Attract flocks to the center
vec3 central = vec3( 0., 0., 0. );
dir = selfPosition - central;
dist = length( dir );
dir.y *= 2.5;
velocity -= normalize( dir ) * delta * 5.;
for ( float y = 0.0; y < height; y++ ) {
for ( float x = 0.0; x < width; x++ ) {
vec2 ref = vec2( x + 0.5, y + 0.5 ) / resolution.xy;
birdPosition = texture2D( texturePosition, ref ).xyz;
dir = birdPosition - selfPosition;
dist = length( dir );
if ( dist < 0.0001 ) continue;
distSquared = dist * dist;
if ( distSquared > zoneRadiusSquared ) continue;
percent = distSquared / zoneRadiusSquared;
if ( percent < separationThresh ) { // low
// Separation - Move apart for comfort
f = ( separationThresh / percent - 1.0 ) * delta;
velocity -= normalize( dir ) * f;
} else if ( percent < alignmentThresh ) { // high
// Alignment - fly the same direction
float threshDelta = alignmentThresh - separationThresh;
float adjustedPercent = ( percent - separationThresh ) / threshDelta;
birdVelocity = texture2D( textureVelocity, ref ).xyz;
f = ( 0.5 - cos( adjustedPercent * PI_2 ) * 0.5 + 0.5 ) * delta;
velocity += normalize( birdVelocity ) * f;
} else {
// Attraction / Cohesion - move closer
float threshDelta = 1.0 - alignmentThresh;
float adjustedPercent;
if( threshDelta == 0. ) adjustedPercent = 1.;
else adjustedPercent = ( percent - alignmentThresh ) / threshDelta;
f = ( 0.5 - ( cos( adjustedPercent * PI_2 ) * -0.5 + 0.5 ) ) * delta;
velocity += normalize( dir ) * f;
}
}
}
// this make tends to fly around than down or up
// if (velocity.y > 0.) velocity.y *= (1. - 0.2 * delta);
// Speed Limits
if ( length( velocity ) > limit ) {
velocity = normalize( velocity ) * limit;
}
gl_FragColor = vec4( velocity, 1.0 );
}
`,
dtVelocity
);
positionVariable = gpuCompute.addVariable(
"texturePosition",
`
uniform float time;
uniform float delta;
void main() {
vec2 uv = gl_FragCoord.xy / resolution.xy;
vec4 tmpPos = texture2D( texturePosition, uv );
vec3 position = tmpPos.xyz;
vec3 velocity = texture2D( textureVelocity, uv ).xyz;
float phase = tmpPos.w;
phase = mod( ( phase + delta +
length( velocity.xz ) * delta * 3. +
max( velocity.y, 0.0 ) * delta * 6. ), 62.83 );
gl_FragColor = vec4( position + velocity * delta * 15. , phase );
}
`,
dtPosition
);
gpuCompute.setVariableDependencies(velocityVariable, [positionVariable, velocityVariable]);
gpuCompute.setVariableDependencies(positionVariable, [positionVariable, velocityVariable]);
positionUniforms = positionVariable.material.uniforms;
velocityUniforms = velocityVariable.material.uniforms;
positionUniforms["time"] = { value: 0 };
positionUniforms["delta"] = { value: 0 };
velocityUniforms["time"] = { value: 1 };
velocityUniforms["delta"] = { value: 0 };
velocityUniforms["testing"] = { value: 1 };
velocityUniforms["separationDistance"] = { value: 1 };
velocityUniforms["alignmentDistance"] = { value: 1 };
velocityUniforms["cohesionDistance"] = { value: 1 };
velocityUniforms["freedomFactor"] = { value: 1 };
velocityUniforms["predator"] = { value: new THREE.Vector3() };
velocityVariable.material.defines.BOUNDS = BOUNDS.toFixed(2);
velocityVariable.wrapS = THREE.RepeatWrapping;
velocityVariable.wrapT = THREE.RepeatWrapping;
positionVariable.wrapS = THREE.RepeatWrapping;
positionVariable.wrapT = THREE.RepeatWrapping;
const error = gpuCompute.init();
if (error !== null) {
console.error(error);
}
}
function initBirds() {
const geometry = new BirdGeometry();
birdUniforms = {
color: { value: new THREE.Color(16720384) },
texturePosition: { value: null },
textureVelocity: { value: null },
time: { value: 1 },
delta: { value: 0 }
};
const material = new THREE.ShaderMaterial({
uniforms: birdUniforms,
vertexShader: `
attribute vec2 reference;
attribute float birdVertex;
attribute vec3 birdColor;
uniform sampler2D texturePosition;
uniform sampler2D textureVelocity;
varying vec4 vColor;
varying float z;
uniform float time;
void main() {
vec4 tmpPos = texture2D( texturePosition, reference );
vec3 pos = tmpPos.xyz;
vec3 velocity = normalize(texture2D( textureVelocity, reference ).xyz);
vec3 newPosition = position;
if ( birdVertex == 4.0 || birdVertex == 7.0 ) {
// flap wings
newPosition.y = sin( tmpPos.w ) * 5.;
}
newPosition = mat3( modelMatrix ) * newPosition;
velocity.z *= -1.;
float xz = length( velocity.xz );
float xyz = 1.;
float x = sqrt( 1. - velocity.y * velocity.y );
float cosry = velocity.x / xz;
float sinry = velocity.z / xz;
float cosrz = x / xyz;
float sinrz = velocity.y / xyz;
mat3 maty = mat3(
cosry, 0, -sinry,
0 , 1, 0 ,
sinry, 0, cosry
);
mat3 matz = mat3(
cosrz , sinrz, 0,
-sinrz, cosrz, 0,
0 , 0 , 1
);
newPosition = maty * matz * newPosition;
newPosition += pos;
z = newPosition.z;
vColor = vec4( birdColor, 1.0 );
gl_Position = projectionMatrix * viewMatrix * vec4( newPosition, 1.0 );
}
`,
fragmentShader: `
varying vec4 vColor;
varying float z;
uniform vec3 color;
void main() {
// Fake colors for now
float z2 = 0.2 + ( 1000. - z ) / 1000. * vColor.x;
gl_FragColor = vec4( z2, z2, z2, 1. );
}
`,
side: THREE.DoubleSide
});
const birdMesh = new THREE.Mesh(geometry, material);
birdMesh.rotation.y = Math.PI / 2;
birdMesh.matrixAutoUpdate = false;
birdMesh.updateMatrix();
scene.add(birdMesh);
}
function fillPositionTexture(texture) {
const theArray = texture.image.data;
for (let k = 0, kl = theArray.length; k < kl; k += 4) {
const x = Math.random() * BOUNDS - BOUNDS_HALF;
const y = Math.random() * BOUNDS - BOUNDS_HALF;
const z = Math.random() * BOUNDS - BOUNDS_HALF;
theArray[k + 0] = x;
theArray[k + 1] = y;
theArray[k + 2] = z;
theArray[k + 3] = 1;
}
}
function fillVelocityTexture(texture) {
const theArray = texture.image.data;
for (let k = 0, kl = theArray.length; k < kl; k += 4) {
const x = Math.random() - 0.5;
const y = Math.random() - 0.5;
const z = Math.random() - 0.5;
theArray[k + 0] = x * 10;
theArray[k + 1] = y * 10;
theArray[k + 2] = z * 10;
theArray[k + 3] = 1;
}
}
function onWindowResize() {
windowHalfX = window.innerWidth / 2;
windowHalfY = window.innerHeight / 2;
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
renderer.setSize(window.innerWidth, window.innerHeight);
}
function onPointerMove(event) {
if (event.isPrimary === false) return;
mouseX = event.clientX - windowHalfX;
mouseY = event.clientY - windowHalfY;
}
function animate() {
render();
stats.update();
}
function render() {
const now = Date.now();
let delta = (now - last) / 1e3;
if (delta > 1) delta = 1;
last = now;
positionUniforms["time"].value = now;
positionUniforms["delta"].value = delta;
velocityUniforms["time"].value = now;
velocityUniforms["delta"].value = delta;
birdUniforms["time"].value = now;
birdUniforms["delta"].value = delta;
velocityUniforms["predator"].value.set(
0.5 * mouseX / windowHalfX,
-0.5 * mouseY / windowHalfY,
0
);
mouseX = 1e4;
mouseY = 1e4;
gpuCompute.compute();
birdUniforms["texturePosition"].value = gpuCompute.getCurrentRenderTarget(positionVariable).texture;
birdUniforms["textureVelocity"].value = gpuCompute.getCurrentRenderTarget(velocityVariable).texture;
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;