参考：Building a WebGL Carousel with React Three Fiber and GSAP

在线 demogithub 源码

效果来源于由 Eum Ray 创建的网站 alcre.co.kr，具有迷人的视觉效果和交互性，具有可拖动或滚动的轮播，具有有趣的图像展示效果。

本文将使用 WebGL、React Three Fiber 和 GSAP 实现类似的效果。通过本文，可以了解如何使用 WebGL、React Three Fiber 和 GSAP 创建交互式 3D 轮播。

(资料图片仅供参考)

准备

首先，用 createreact app创建项目

npx create-react-app webgl-carsouelcd webgl-carsouelnpm start

然后安装相关依赖

npm i @react-three/fiber @react-three/drei gsap leva react-use -S

@react-three/fiber: 用 react 实现的简化 three.js 写法的一个非常出名的库@react-three/drei：@react-three/fiber 生态中的一个非常有用的库，是对 @react-three/fiber 的增强gsap: 一个非常出名的动画库leva: @react-three/fiber 生态中用以在几秒钟内创建GUI控件的库react-use: 一个流行的 react hooks 库1. 生成具有纹理的 3D 平面

首先，创建一个任意大小的平面，放置于原点（0, 0, 0）并面向相机。然后，使用 shaderMaterial材质将所需图像插入到材质中，修改 UV 位置，让图像填充整个几何体表面。

为了实现这一点，需要使用一个 glsl 函数，函数将平面和图像的比例作为转换参数：

/* --------------------------------Background Cover UV--------------------------------u = basic UVs = plane sizei = image size*/vec2 CoverUV(vec2 u, vec2 s, vec2 i) {  float rs = s.x / s.y; // aspect plane size  float ri = i.x / i.y; // aspect image size  vec2 st = rs < ri ? vec2(i.x * s.y / i.y, s.y) : vec2(s.x, i.y * s.x / i.x); // new st  vec2 o = (rs < ri ? vec2((st.x - s.x) / 2.0, 0.0) : vec2(0.0, (st.y - s.y) / 2.0)) / st; // offset  return u * s / st + o;}

接下来，将定义2个 uniforms：uRes和 uImageRes。每当改变视口大小时，这2个变量将会随之改变。使用 uRes以像素为单位存储片面的大小，使用 uImageRes存储图像纹理的大小。

下面是创建平面和设置着色器材质的代码：

// Plane.jsimport { useEffect, useMemo, useRef } from "react"import { useThree } from "@react-three/fiber"import { useTexture } from "@react-three/drei"import { useControls } from "leva"const Plane = () => {  const $mesh = useRef()  const { viewport } = useThree()  const tex = useTexture(    "https://raw.githubusercontent.com/supahfunk/webgl-carousel/main/public/img/1.jpg"  )  const { width, height } = useControls({    width: {      value: 2,      min: 0.5,      max: viewport.width,    },    height: {      value: 3,      min: 0.5,      max: viewport.height,    }  })  useEffect(() => {    if ($mesh.current.material) {      $mesh.current.material.uniforms.uRes.value.x = width      $mesh.current.material.uniforms.uRes.value.y = height    }  }, [viewport, width, height])  const shaderArgs = useMemo(() => ({    uniforms: {      uTex: { value: tex },      uRes: { value: { x: 1, y: 1 } },      uImageRes: {        value: { x: tex.source.data.width, y: tex.source.data.height }      }    },    vertexShader: /* glsl */ `      varying vec2 vUv;      void main() {        vUv = uv;        vec3 pos = position;        gl_Position = projectionMatrix * modelViewMatrix * vec4( pos, 1.0 );      }    `,    fragmentShader: /* glsl */ `      uniform sampler2D uTex;      uniform vec2 uRes;      uniform vec2 uImageRes;      /*      -------------------------------------      background Cover UV      -------------------------------------      u = basic UV      s = screen size      i = image size      */      vec2 CoverUV(vec2 u, vec2 s, vec2 i) {        float rs = s.x / s.y; // aspect screen size        float ri = i.x / i.y; // aspect image size        vec2 st = rs < ri ? vec2(i.x * s.y / i.y, s.y) : vec2(s.x, i.y * s.x / i.x); // new st        vec2 o = (rs < ri ? vec2((st.x - s.x) / 2.0, 0.0) : vec2(0.0, (st.y - s.y) / 2.0)) / st; // offset        return u * s / st + o;      }      varying vec2 vUv;      void main() {        vec2 uv = CoverUV(vUv, uRes, uImageRes);        vec3 tex = texture2D(uTex, uv).rgb;        gl_FragColor = vec4(tex, 1.0);      }    `  }), [tex])  return (                      )}export default Plane

2、向平面添加缩放效果

首先， 设置一个新组件来包裹 ，用以管理缩放效果的激活和停用。

使用着色器材质 shaderMaterial调整 mesh大小可保持几何空间的尺寸。因此，激活缩放效果后，必须显示一个新的透明平面，其尺寸与视口相当，方便点击整个图像恢复到初始状态。

此外，还需要在平面的着色器中实现波浪效果。

因此，在 uniforms中添加一个新字段 uZoomScale，存储缩放平面的值 x、y，从而得到顶点着色器的位置。缩放值通过在平面尺寸和视口尺寸比例来计算：

$mesh.current.material.uniforms.uZoomScale.value.x = viewport.width / width$mesh.current.material.uniforms.uZoomScale.value.y = viewport.height / height

接下来，在 uniforms中添加一个新字段 uProgress，来控制波浪效果的数量。通过使用 GSAP 修改 uProgress，动画实现平滑的缓动效果。

创建波形效果，可以在顶点着色器中使用 sin函数，函数在平面的 x 和 y 位置上添加波状运动。

// CarouselItem.jsimport { useEffect, useRef, useState } from "react"import { useThree } from "@react-three/fiber"import gsap from "gsap"import Plane from "./Plane"const CarouselItem = () => {  const $root = useRef()  const [hover, setHover] = useState(false)  const [isActive, setIsActive] = useState(false)  const { viewport } = useThree()  useEffect(() => {    gsap.killTweensOf($root.current.position)    gsap.to($root.current.position, {      z: isActive ? 0 : -0.01,      duration: 0.2,      ease: "power3.out",      delay: isActive ? 0 : 2    })  }, [isActive])  // hover effect  useEffect(() => {    const hoverScale = hover && !isActive ? 1.1 : 1    gsap.to($root.current.scale, {      x: hoverScale,      y: hoverScale,      duration: 0.5,      ease: "power3.out"    })  }, [hover, isActive])  const handleClose = (e) => {    e.stopPropagation()    if (!isActive) return    setIsActive(false)  }  const textureUrl = "https://raw.githubusercontent.com/supahfunk/webgl-carousel/main/public/img/1.jpg"  return (     setIsActive(true)}      onPointerEnter={() => setHover(true)}      onPointerLeave={() => setHover(false)}    >            {isActive ? (                                          ) : null}      )}export default CarouselItem

组件也要进行更改，支持参数及参数变更处理，更改后：

// Plane.jsimport { useEffect, useMemo, useRef } from "react"import { useThree } from "@react-three/fiber"import { useTexture } from "@react-three/drei"import gsap from "gsap"const Plane = ({ texture, width, height, active, ...props}) => {  const $mesh = useRef()  const { viewport } = useThree()  const tex = useTexture(texture)  useEffect(() => {    if ($mesh.current.material) {      // setting      $mesh.current.material.uniforms.uZoomScale.value.x = viewport.width / width      $mesh.current.material.uniforms.uZoomScale.value.y = viewport.height / height      gsap.to($mesh.current.material.uniforms.uProgress, {        value: active ? 1 : 0,        duration: 2.5,        ease: "power3.out"      })      gsap.to($mesh.current.material.uniforms.uRes.value, {        x: active ? viewport.width : width,        y: active? viewport.height : height,        duration: 2.5,        ease: "power3.out"      })    }  }, [viewport, active]);  const shaderArgs = useMemo(() => ({    uniforms: {      uProgress: { value: 0 },      uZoomScale: { value: { x: 1, y: 1 } },      uTex: { value: tex },      uRes: { value: { x: 1, y: 1 } },      uImageRes: {        value: { x: tex.source.data.width, y: tex.source.data.height }      }    },    vertexShader: /* glsl */ `      varying vec2 vUv;      uniform float uProgress;      uniform vec2 uZoomScale;      void main() {        vUv = uv;        vec3 pos = position;        float angle = uProgress * 3.14159265 / 2.;        float wave = cos(angle);        float c = sin(length(uv - .5) * 15. + uProgress * 12.) * .5 + .5;        pos.x *= mix(1., uZoomScale.x + wave * c, uProgress);        pos.y *= mix(1., uZoomScale.y + wave * c, uProgress);        gl_Position = projectionMatrix * modelViewMatrix * vec4( pos, 1.0 );      }    `,    fragmentShader: /* glsl */ `      uniform sampler2D uTex;      uniform vec2 uRes;      // uniform vec2 uZoomScale;      uniform vec2 uImageRes;      /*      -------------------------------------      background Cover UV      -------------------------------------      u = basic UV      s = screen size      i = image size      */      vec2 CoverUV(vec2 u, vec2 s, vec2 i) {        float rs = s.x / s.y; // aspect screen size        float ri = i.x / i.y; // aspect image size        vec2 st = rs < ri ? vec2(i.x * s.y / i.y, s.y) : vec2(s.x, i.y * s.x / i.x); // new st        vec2 o = (rs < ri ? vec2((st.x - s.x) / 2.0, 0.0) : vec2(0.0, (st.y - s.y) / 2.0)) / st; // offset        return u * s / st + o;      }      varying vec2 vUv;      void main() {        vec2 uv = CoverUV(vUv, uRes, uImageRes);        vec3 tex = texture2D(uTex, uv).rgb;        gl_FragColor = vec4(tex, 1.0);      }    `  }), [tex])  return (                      )}export default Plane

3、实现可以用鼠标滚动或拖动移动的图像轮播

这部分是最有趣的，但也是最复杂的，因为必须考虑很多事情。

首先，需要使用 renderSlider创建一个组用以包含所有图像，图像用 渲染。然后，需要使用 renderPlaneEvent()创建一个片面用以管理事件。

轮播最重要的部分在 useFrame()中，需要计算滑块进度，使用 displayItems()函数设置所有item位置。

另一个需要考虑的重要方面是 的 z位置，当它变为活动状态时，需要使其 z位置更靠近相机，以便缩放效果不会与其他 meshs冲突。这也是为什么当退出缩放时，需要 mesh足够小以将 z轴位置恢复为 0 (详见 )。也是为什么禁用其他 meshs的点击，直到缩放效果被停用。

// data/images.jsconst images = [  { image: "https://raw.githubusercontent.com/supahfunk/webgl-carousel/main/public/img/1.jpg" },  { image: "https://raw.githubusercontent.com/supahfunk/webgl-carousel/main/public/img/2.jpg" },  { image: "https://raw.githubusercontent.com/supahfunk/webgl-carousel/main/public/img/3.jpg" },  { image: "https://raw.githubusercontent.com/supahfunk/webgl-carousel/main/public/img/4.jpg" },  { image: "https://raw.githubusercontent.com/supahfunk/webgl-carousel/main/public/img/5.jpg" },  { image: "https://raw.githubusercontent.com/supahfunk/webgl-carousel/main/public/img/6.jpg" },  { image: "https://raw.githubusercontent.com/supahfunk/webgl-carousel/main/public/img/7.jpg" },  { image: "https://raw.githubusercontent.com/supahfunk/webgl-carousel/main/public/img/8.jpg" },  { image: "https://raw.githubusercontent.com/supahfunk/webgl-carousel/main/public/img/9.jpg" },  { image: "https://raw.githubusercontent.com/supahfunk/webgl-carousel/main/public/img/10.jpg" },  { image: "https://raw.githubusercontent.com/supahfunk/webgl-carousel/main/public/img/11.jpg" },  { image: "https://raw.githubusercontent.com/supahfunk/webgl-carousel/main/public/img/12.jpg" }]export default images

// Carousel.jsimport { useEffect, useRef, useState, useMemo } from "react";import { useFrame, useThree } from "@react-three/fiber";import { usePrevious } from "react-use"import gsap from "gsap"import CarouselItem from "./CarouselItem"import images from "../data/images"// Plane settingsconst planeSettings = {  width: 1,  height: 2.5,  gap: 0.1}// gsap defaultsgsap.defaults({  duration: 2.5,  ease: "power3.out"})const Carousel = () => {  const [$root, setRoot] = useState();  const [activePlane, setActivePlane] = useState(null);  const prevActivePlane = usePrevious(activePlane)  const { viewport } = useThree()  // vars  const progress = useRef(0)  const startX = useRef(0)  const isDown = useRef(false)  const speedWheel = 0.02  const speedDrag = -0.3  const $items = useMemo(() => {    if ($root) return $root.children  }, [$root])  const displayItems = (item, index, active) => {    gsap.to(item.position, {      x: (index - active) * (planeSettings.width + planeSettings.gap),      y: 0    })  }  useFrame(() => {    progress.current = Math.max(0, Math.min(progress.current, 100))    const active = Math.floor((progress.current / 100) * ($items.length - 1))    $items.forEach((item, index) => displayItems(item, index, active))  })  const handleWheel = (e) => {    if (activePlane !== null) return    const isVerticalScroll = Math.abs(e.deltaY) > Math.abs(e.deltaX)    const wheelProgress = isVerticalScroll ? e.deltaY : e.deltaX    progress.current = progress.current + wheelProgress * speedWheel  }  const handleDown = (e) => {    if (activePlane !== null) return    isDown.current = true    startX.current = e.clientX || (e.touches && e.touches[0].clientX) || 0  }  const handleUp = () => {    isDown.current = false  }  const handleMove = (e) => {    if (activePlane !== null || !isDown.current) return    const x = e.clientX || (e.touches && e.touches[0].clientX) || 0    const mouseProgress = (x - startX.current) * speedDrag    progress.current = progress.current + mouseProgress    startX.current = x  }  // click  useEffect(() => {    if (!$items) return    if (activePlane !== null && prevActivePlane === null) {      progress.current = (activePlane / ($items.length - 1)) * 100    }  }, [activePlane, $items]);  const renderPlaneEvents = () => {    return (                                )  }  const renderSlider = () => {    return (              {images.map((item, i) => (                  ))}          )  }  return (          {renderPlaneEvents()}      {renderSlider()}      )}export default Carousel

需要更改，以便根据参数显示不同的图像，及其他细节处理，更改后如下：

// CarouselItem.jsimport { useEffect, useRef, useState } from "react"import { useThree } from "@react-three/fiber"import gsap from "gsap"import Plane from "./Plane"const CarouselItem = ({  index,  width,  height,  setActivePlane,  activePlane,  item}) => {  const $root = useRef()  const [hover, setHover] = useState(false)  const [isActive, setIsActive] = useState(false)  const [isCloseActive, setIsCloseActive] = useState(false);  const { viewport } = useThree()  const timeoutID = useRef()  useEffect(() => {    if (activePlane === index) {      setIsActive(activePlane === index)      setIsCloseActive(true)    } else {      setIsActive(null)    }  }, [activePlane]);    useEffect(() => {    gsap.killTweensOf($root.current.position)    gsap.to($root.current.position, {      z: isActive ? 0 : -0.01,      duration: 0.2,      ease: "power3.out",      delay: isActive ? 0 : 2    })  }, [isActive])  // hover effect  useEffect(() => {    const hoverScale = hover && !isActive ? 1.1 : 1    gsap.to($root.current.scale, {      x: hoverScale,      y: hoverScale,      duration: 0.5,      ease: "power3.out"    })  }, [hover, isActive])  const handleClose = (e) => {    e.stopPropagation()    if (!isActive) return    setActivePlane(null)    setHover(false)    clearTimeout(timeoutID.current)    timeoutID.current = setTimeout(() => {      setIsCloseActive(false)    }, 1500);    // 这个计时器的持续时间取决于 plane 关闭动画的时间  }  return (     setActivePlane(index)}      onPointerEnter={() => setHover(true)}      onPointerLeave={() => setHover(false)}    >            {isCloseActive ? (                                          ) : null}      )}export default CarouselItem

4、实现后期处理效果，增强轮播体验

真正吸引我眼球并激发我复制次轮播的是视口边缘拉伸像素的效果。

过去，我通过 @react-three/postprocessing 来自定义着色器多次实现此效果。然而，最近我一直在使用 MeshTransmissionMaterial，因此有了一个想法，尝试用这种材料覆盖 mesh并调整设置实现效果。效果几乎相同！

诀窍是将 material的 thickness属性与轮播滚动进度的速度联系起来，仅此而已。

// PostProcessing.jsimport { forwardRef } from "react";import { useThree } from "@react-three/fiber";import { MeshTransmissionMaterial } from "@react-three/drei";import { Color } from "three";import { useControls } from "leva"const PostProcessing = forwardRef((_, ref) => {  const { viewport } = useThree()  const { active, ior } = useControls({    active: { value: true },    ior: {      value: 0.9,      min: 0.8,      max: 1.2    }  })  return active ? (                      ) : null})export default PostProcessing

因为后处理作用于 组件，所以需要进行相应的更改，更改后如下：

// Carousel.jsimport { useEffect, useRef, useState, useMemo } from "react";import { useFrame, useThree } from "@react-three/fiber";import { usePrevious } from "react-use"import gsap from "gsap"import PostProcessing from "./PostProcessing";import CarouselItem from "./CarouselItem"import { lerp, getPiramidalIndex } from "../utils";import images from "../data/images"// Plane settingsconst planeSettings = {  width: 1,  height: 2.5,  gap: 0.1}// gsap defaultsgsap.defaults({  duration: 2.5,  ease: "power3.out"})const Carousel = () => {  const [$root, setRoot] = useState();  const $post = useRef()  const [activePlane, setActivePlane] = useState(null);  const prevActivePlane = usePrevious(activePlane)  const { viewport } = useThree()  // vars  const progress = useRef(0)  const startX = useRef(0)  const isDown = useRef(false)  const speedWheel = 0.02  const speedDrag = -0.3  const oldProgress = useRef(0)  const speed = useRef(0)  const $items = useMemo(() => {    if ($root) return $root.children  }, [$root])  const displayItems = (item, index, active) => {    const piramidalIndex = getPiramidalIndex($items, active)[index]    gsap.to(item.position, {      x: (index - active) * (planeSettings.width + planeSettings.gap),      y: $items.length * -0.1 + piramidalIndex * 0.1    })  }  useFrame(() => {    progress.current = Math.max(0, Math.min(progress.current, 100))    const active = Math.floor((progress.current / 100) * ($items.length - 1))    $items.forEach((item, index) => displayItems(item, index, active))    speed.current = lerp(speed.current, Math.abs(oldProgress.current - progress.current), 0.1)    oldProgress.current = lerp(oldProgress.current, progress.current, 0.1)    if ($post.current) {      $post.current.thickness = speed.current    }  })  const handleWheel = (e) => {    if (activePlane !== null) return    const isVerticalScroll = Math.abs(e.deltaY) > Math.abs(e.deltaX)    const wheelProgress = isVerticalScroll ? e.deltaY : e.deltaX    progress.current = progress.current + wheelProgress * speedWheel  }  const handleDown = (e) => {    if (activePlane !== null) return    isDown.current = true    startX.current = e.clientX || (e.touches && e.touches[0].clientX) || 0  }  const handleUp = () => {    isDown.current = false  }  const handleMove = (e) => {    if (activePlane !== null || !isDown.current) return    const x = e.clientX || (e.touches && e.touches[0].clientX) || 0    const mouseProgress = (x - startX.current) * speedDrag    progress.current = progress.current + mouseProgress    startX.current = x  }  // click  useEffect(() => {    if (!$items) return    if (activePlane !== null && prevActivePlane === null) {      progress.current = (activePlane / ($items.length - 1)) * 100    }  }, [activePlane, $items]);  const renderPlaneEvents = () => {    return (                                )  }  const renderSlider = () => {    return (              {images.map((item, i) => (                  ))}          )  }  return (          {renderPlaneEvents()}      {renderSlider()}            )}export default Carousel

// utils/index.js/** * 返回 v0, v1 之间的一个值，可以根据 t 进行计算 * 示例： * lerp(5, 10, 0) // 5 * lerp(5, 10, 1) // 10 * lerp(5, 10, 0.2) // 6 */export const lerp = (v0, v1, t) => v0 * (1 - t) + v1 * t/** * 以金字塔形状返回索引值递减的数组，从具有最大值的指定索引开始。这些索引通常用于在元素之间创建重叠效果 * 示例：array = [0, 1, 2, 3, 4, 5] * getPiramidalIndex(array, 0) // [ 6, 5, 4, 3, 2, 1 ] * getPiramidalIndex(array, 1) // [ 5, 6, 5, 4, 3, 2 ] * getPiramidalIndex(array, 2) // [ 4, 5, 6, 5, 4, 3 ] * getPiramidalIndex(array, 3) // [ 3, 4, 5, 6, 5, 4 ] * getPiramidalIndex(array, 4) // [ 2, 3, 4, 5, 6, 5 ] * getPiramidalIndex(array, 5) // [ 1, 2, 3, 4, 5, 6 ] */export const getPiramidalIndex = (array, index) => {  return array.map((_, i) => index === i ? array.length : array.length - Math.abs(index - i))}

总之，通过使用 React Three Fiber 、GSAP 和一些创造力，可以在 WebGL 中创建令人惊叹的视觉效果和交互式组件，就像受 alcre.co.kr 启发的轮播一样。希望这篇文章对您自己的项目有所帮助和启发！