webgl_volume_instancing
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 { OrbitControls } from "three/examples/jsm/controls/OrbitControls.js";
import { VOXLoader, VOXData3DTexture } from "three/examples/jsm/loaders/VOXLoader.js";
/** @type {import("@minisheeep/mp-three-examples").OfficialExampleInfo} */
const exampleInfo = {
name: "webgl_volume_instancing",
useLoaders: [VOXLoader],
info: [
[
{
tag: "a",
link: "https://threejs.org",
content: "three.js"
},
{
tag: "text",
content: "webgl2 - volume - instancing"
}
]
],
init: ({ window, canvas, GUI, Stats, needToDispose, useFrame }) => {
let renderer, scene, camera, controls, clock;
init();
function init() {
renderer = new THREE.WebGLRenderer({ canvas });
renderer.setPixelRatio(window.devicePixelRatio);
renderer.setSize(window.innerWidth, window.innerHeight);
renderer.setAnimationLoop(animate);
scene = new THREE.Scene();
camera = new THREE.PerspectiveCamera(60, window.innerWidth / window.innerHeight, 0.1, 1e3);
camera.position.set(0, 0, 4);
controls = new OrbitControls(camera, renderer.domElement);
controls.autoRotate = true;
controls.autoRotateSpeed = -1;
controls.enableDamping = true;
clock = new THREE.Clock();
const vertexShader = (
/* glsl */
`
in vec3 position;
in mat4 instanceMatrix;
uniform mat4 modelMatrix;
uniform mat4 modelViewMatrix;
uniform mat4 projectionMatrix;
uniform vec3 cameraPos;
out vec3 vOrigin;
out vec3 vDirection;
void main() {
vec4 mvPosition = modelViewMatrix * instanceMatrix * vec4( position, 1.0 );
vOrigin = vec3( inverse( instanceMatrix * modelMatrix ) * vec4( cameraPos, 1.0 ) ).xyz;
vDirection = position - vOrigin;
gl_Position = projectionMatrix * mvPosition;
}
`
);
const fragmentShader = (
/* glsl */
`
precision highp float;
precision highp sampler3D;
uniform mat4 modelViewMatrix;
uniform mat4 projectionMatrix;
in vec3 vOrigin;
in vec3 vDirection;
out vec4 color;
uniform sampler3D map;
uniform float threshold;
uniform float steps;
vec2 hitBox( vec3 orig, vec3 dir ) {
const vec3 box_min = vec3( - 0.5 );
const vec3 box_max = vec3( 0.5 );
vec3 inv_dir = 1.0 / dir;
vec3 tmin_tmp = ( box_min - orig ) * inv_dir;
vec3 tmax_tmp = ( box_max - orig ) * inv_dir;
vec3 tmin = min( tmin_tmp, tmax_tmp );
vec3 tmax = max( tmin_tmp, tmax_tmp );
float t0 = max( tmin.x, max( tmin.y, tmin.z ) );
float t1 = min( tmax.x, min( tmax.y, tmax.z ) );
return vec2( t0, t1 );
}
float sample1( vec3 p ) {
return texture( map, p ).r;
}
#define epsilon .0001
vec3 normal( vec3 coord ) {
if ( coord.x < epsilon ) return vec3( 1.0, 0.0, 0.0 );
if ( coord.y < epsilon ) return vec3( 0.0, 1.0, 0.0 );
if ( coord.z < epsilon ) return vec3( 0.0, 0.0, 1.0 );
if ( coord.x > 1.0 - epsilon ) return vec3( - 1.0, 0.0, 0.0 );
if ( coord.y > 1.0 - epsilon ) return vec3( 0.0, - 1.0, 0.0 );
if ( coord.z > 1.0 - epsilon ) return vec3( 0.0, 0.0, - 1.0 );
float step = 0.01;
float x = sample1( coord + vec3( - step, 0.0, 0.0 ) ) - sample1( coord + vec3( step, 0.0, 0.0 ) );
float y = sample1( coord + vec3( 0.0, - step, 0.0 ) ) - sample1( coord + vec3( 0.0, step, 0.0 ) );
float z = sample1( coord + vec3( 0.0, 0.0, - step ) ) - sample1( coord + vec3( 0.0, 0.0, step ) );
return normalize( vec3( x, y, z ) );
}
void main(){
vec3 rayDir = normalize( vDirection );
vec2 bounds = hitBox( vOrigin, rayDir );
if ( bounds.x > bounds.y ) discard;
bounds.x = max( bounds.x, 0.0 );
vec3 p = vOrigin + bounds.x * rayDir;
vec3 inc = 1.0 / abs( rayDir );
float delta = min( inc.x, min( inc.y, inc.z ) );
delta /= 50.0;
for ( float t = bounds.x; t < bounds.y; t += delta ) {
float d = sample1( p + 0.5 );
if ( d > 0.5 ) {
color.rgb = p * 2.0; // normal( p + 0.5 ); // * 0.5 + ( p * 1.5 + 0.25 );
color.a = 1.;
break;
}
p += rayDir * delta;
}
if ( color.a == 0.0 ) discard;
}
`
);
const loader = new VOXLoader();
loader.load("models/vox/menger.vox", function(chunks) {
for (let i = 0; i < chunks.length; i++) {
const chunk = chunks[i];
const geometry = new THREE.BoxGeometry(1, 1, 1);
const material = new THREE.RawShaderMaterial({
glslVersion: THREE.GLSL3,
uniforms: {
map: { value: new VOXData3DTexture(chunk) },
cameraPos: { value: new THREE.Vector3() }
},
vertexShader,
fragmentShader,
side: THREE.BackSide
});
const mesh = new THREE.InstancedMesh(geometry, material, 5e4);
mesh.onBeforeRender = function() {
this.material.uniforms.cameraPos.value.copy(camera.position);
};
const transform = new THREE.Object3D();
for (let i2 = 0; i2 < mesh.count; i2++) {
transform.position.random().subScalar(0.5).multiplyScalar(150);
transform.rotation.x = Math.random() * Math.PI;
transform.rotation.y = Math.random() * Math.PI;
transform.rotation.z = Math.random() * Math.PI;
transform.updateMatrix();
mesh.setMatrixAt(i2, transform.matrix);
}
scene.add(mesh);
}
});
window.addEventListener("resize", onWindowResize);
needToDispose(renderer, controls, scene, loader);
}
function onWindowResize() {
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
renderer.setSize(window.innerWidth, window.innerHeight);
}
function animate() {
const delta = clock.getDelta();
controls.update(delta);
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;