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webgl_texture3d_partialupdate

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 { ImprovedNoise } from "three/examples/jsm/math/ImprovedNoise.js";

/** @type {import("@minisheeep/mp-three-examples").OfficialExampleInfo} */
const exampleInfo = {
  name: "webgl_texture3d_partialupdate",
  useLoaders: [],
  info: [
    [
      {
        tag: "a",
        link: "https://threejs.org",
        content: "three.js"
      },
      {
        tag: "text",
        content: "webgl2 - volume - cloud"
      }
    ]
  ],
  init: ({ window, canvas: rendererCanvas, GUI, Stats, needToDispose, useFrame }) => {
    const INITIAL_CLOUD_SIZE = 128;
    let renderer, scene, camera;
    let mesh;
    let prevTime = Date.now();
    let cloudTexture = null;
    init();
    function generateCloudTexture(size, scaleFactor = 1) {
      const data = new Uint8Array(size * size * size);
      const scale = scaleFactor * 10 / size;
      let i = 0;
      const perlin = new ImprovedNoise();
      const vector = new THREE.Vector3();
      for (let z = 0; z < size; z++) {
        for (let y = 0; y < size; y++) {
          for (let x = 0; x < size; x++) {
            const dist = vector.set(x, y, z).subScalar(size / 2).divideScalar(size).length();
            const fadingFactor = (1 - dist) * (1 - dist);
            data[i] = (128 + 128 * perlin.noise(x * scale / 1.5, y * scale, z * scale / 1.5)) * fadingFactor;
            i++;
          }
        }
      }
      return new THREE.Data3DTexture(data, size, size, size);
    }
    function init() {
      renderer = new THREE.WebGLRenderer({ canvas: rendererCanvas });
      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, 100);
      camera.position.set(0, 0, 1.5);
      new OrbitControls(camera, renderer.domElement);
      const canvas = document.createElement("canvas");
      canvas.width = 1;
      canvas.height = 32;
      const context = canvas.getContext("2d");
      const gradient = context.createLinearGradient(0, 0, 0, 32);
      gradient.addColorStop(0, "#014a84");
      gradient.addColorStop(0.5, "#0561a0");
      gradient.addColorStop(1, "#437ab6");
      context.fillStyle = gradient;
      context.fillRect(0, 0, 1, 32);
      const skyMap = new THREE.CanvasTexture(canvas);
      skyMap.colorSpace = THREE.SRGBColorSpace;
      const sky = new THREE.Mesh(
        new THREE.SphereGeometry(10),
        new THREE.MeshBasicMaterial({ map: skyMap, side: THREE.BackSide })
      );
      scene.add(sky);
      const texture = new THREE.Data3DTexture(
        new Uint8Array(INITIAL_CLOUD_SIZE * INITIAL_CLOUD_SIZE * INITIAL_CLOUD_SIZE).fill(0),
        INITIAL_CLOUD_SIZE,
        INITIAL_CLOUD_SIZE,
        INITIAL_CLOUD_SIZE
      );
      texture.format = THREE.RedFormat;
      texture.minFilter = THREE.LinearFilter;
      texture.magFilter = THREE.LinearFilter;
      texture.unpackAlignment = 1;
      texture.needsUpdate = true;
      cloudTexture = texture;
      const vertexShader = (
        /* glsl */
        `
					in vec3 position;

					uniform mat4 modelMatrix;
					uniform mat4 modelViewMatrix;
					uniform mat4 projectionMatrix;
					uniform vec3 cameraPos;

					out vec3 vOrigin;
					out vec3 vDirection;

					void main() {
						vec4 mvPosition = modelViewMatrix * vec4( position, 1.0 );

						vOrigin = vec3( inverse( 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 vec3 base;
					uniform sampler3D map;

					uniform float threshold;
					uniform float range;
					uniform float opacity;
					uniform float steps;
					uniform float frame;

					uint wang_hash(uint seed)
					{
							seed = (seed ^ 61u) ^ (seed >> 16u);
							seed *= 9u;
							seed = seed ^ (seed >> 4u);
							seed *= 0x27d4eb2du;
							seed = seed ^ (seed >> 15u);
							return seed;
					}

					float randomFloat(inout uint seed)
					{
							return float(wang_hash(seed)) / 4294967296.;
					}

					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;
					}

					float shading( vec3 coord ) {
						float step = 0.01;
						return sample1( coord + vec3( - step ) ) - sample1( coord + vec3( step ) );
					}

					vec4 linearToSRGB( in vec4 value ) {
						return vec4( mix( pow( value.rgb, vec3( 0.41666 ) ) * 1.055 - vec3( 0.055 ), value.rgb * 12.92, vec3( lessThanEqual( value.rgb, vec3( 0.0031308 ) ) ) ), value.a );
					}

					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 /= steps;

						// Jitter

						// Nice little seed from
						// https://blog.demofox.org/2020/05/25/casual-shadertoy-path-tracing-1-basic-camera-diffuse-emissive/
						uint seed = uint( gl_FragCoord.x ) * uint( 1973 ) + uint( gl_FragCoord.y ) * uint( 9277 ) + uint( frame ) * uint( 26699 );
						vec3 size = vec3( textureSize( map, 0 ) );
						float randNum = randomFloat( seed ) * 2.0 - 1.0;
						p += rayDir * randNum * ( 1.0 / size );

						//

						vec4 ac = vec4( base, 0.0 );

						for ( float t = bounds.x; t < bounds.y; t += delta ) {

							float d = sample1( p + 0.5 );

							d = smoothstep( threshold - range, threshold + range, d ) * opacity;

							float col = shading( p + 0.5 ) * 3.0 + ( ( p.x + p.y ) * 0.25 ) + 0.2;

							ac.rgb += ( 1.0 - ac.a ) * d * col;

							ac.a += ( 1.0 - ac.a ) * d;

							if ( ac.a >= 0.95 ) break;

							p += rayDir * delta;

						}

						color = linearToSRGB( ac );

						if ( color.a == 0.0 ) discard;

					}
				`
      );
      const geometry = new THREE.BoxGeometry(1, 1, 1);
      const material = new THREE.RawShaderMaterial({
        glslVersion: THREE.GLSL3,
        uniforms: {
          base: { value: new THREE.Color(7965344) },
          map: { value: texture },
          cameraPos: { value: new THREE.Vector3() },
          threshold: { value: 0.25 },
          opacity: { value: 0.25 },
          range: { value: 0.1 },
          steps: { value: 100 },
          frame: { value: 0 }
        },
        vertexShader,
        fragmentShader,
        side: THREE.BackSide,
        transparent: true
      });
      mesh = new THREE.Mesh(geometry, material);
      scene.add(mesh);
      const parameters = {
        threshold: 0.25,
        opacity: 0.25,
        range: 0.1,
        steps: 100
      };
      function update() {
        material.uniforms.threshold.value = parameters.threshold;
        material.uniforms.opacity.value = parameters.opacity;
        material.uniforms.range.value = parameters.range;
        material.uniforms.steps.value = parameters.steps;
      }
      const gui = new GUI();
      gui.add(parameters, "threshold", 0, 1, 0.01).onChange(update);
      gui.add(parameters, "opacity", 0, 1, 0.01).onChange(update);
      gui.add(parameters, "range", 0, 1, 0.01).onChange(update);
      gui.add(parameters, "steps", 0, 200, 1).onChange(update);
      window.addEventListener("resize", onWindowResize);
      needToDispose(renderer, scene);
    }
    function onWindowResize() {
      camera.aspect = window.innerWidth / window.innerHeight;
      camera.updateProjectionMatrix();
      renderer.setSize(window.innerWidth, window.innerHeight);
    }
    let curr = 0;
    const countPerRow = 4;
    const countPerSlice = countPerRow * countPerRow;
    const sliceCount = 4;
    const totalCount = sliceCount * countPerSlice;
    const margins = 8;
    const perElementPaddedSize = (INITIAL_CLOUD_SIZE - margins) / countPerRow;
    const perElementSize = Math.floor((INITIAL_CLOUD_SIZE - 1) / countPerRow);
    function animate() {
      const time = Date.now();
      if (time - prevTime > 1500 && curr < totalCount) {
        const position = new THREE.Vector3(
          Math.floor(curr % countPerRow) * perElementSize + margins * 0.5,
          Math.floor(curr % countPerSlice / countPerRow) * perElementSize + margins * 0.5,
          Math.floor(curr / countPerSlice) * perElementSize + margins * 0.5
        ).floor();
        const maxDimension = perElementPaddedSize - 1;
        const box = new THREE.Box3(
          new THREE.Vector3(0, 0, 0),
          new THREE.Vector3(maxDimension, maxDimension, maxDimension)
        );
        const scaleFactor = (Math.random() + 0.5) * 0.5;
        const source = generateCloudTexture(perElementPaddedSize, scaleFactor);
        renderer.copyTextureToTexture3D(source, cloudTexture, box, position);
        prevTime = time;
        curr++;
      }
      mesh.material.uniforms.cameraPos.value.copy(camera.position);
      mesh.material.uniforms.frame.value++;
      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;