使用 React-Three-Fiber

Question

我目前正在使用 React Three Fiber 来简单地渲染太阳和围绕它运行的地球以对其进行测试。但是，每次我运行开发服务器进行测试时，我都添加了将纹理应用于各个球体的代码，球体无法渲染。我试过寻找有同样问题的人，但没有任何运气。这是我的程序代码。

import React, { useRef, useState } from 'react'
import { Canvas, useFrame, useLoader } from 'react-three-fiber'
import { TextureLoader } from 'three/src/loaders/TextureLoader'
import { useTexture } from "@react-three/drei";

function Sun(props) {
  const [colorMap] = useTexture(['Sun_texture.jpg'])
  const mesh = useRef()
  const [state, setState] = useState({ isHovered: false, isActive: false })
  useFrame((state) => {
    const time = state.clock.getElapsedTime()
    mesh.current.rotation.z = 0
    mesh.current.rotation.x = 0
    mesh.current.rotation.y = time / 5
  })

  return (
    <mesh
      {...props}
      ref={mesh}
      
      scale={[1, 1, 1]}
      onPointerOver={(e) => setState({ ...state, isHovered: true })}
      onPointerOut={(e) => setState({ ...state, isHovered: false })}>
      <sphereGeometry args={[0.5, 100, 100]} map={colorMap} />
      <meshStandardMaterial map={colorMap} transparent={true} emissive={'#444444'} emissiveIntensity={0.3}/>
    </mesh>
  )
}

function Earth(props) {
  const mesh = useRef()
  const [state, setState] = useState({ isHovered: false, isActive: false })
  const [colorMap] = useTexture(['Earth_texture.jpg'])
  useFrame((state) => {
    const time = state.clock.getElapsedTime()
    mesh.current.position.x = 4 * Math.sin(time / 10)
    mesh.current.position.y = 0
    mesh.current.position.z = 4 * Math.cos(time / 10)
    mesh.current.rotation.z = 0
    mesh.current.rotation.x = 0
    mesh.current.rotation.y = time / 2
  })

  return (
    <mesh
      {...props}
      ref={mesh}
      scale={[0.5, 0.5, 0.5]}
      onPointerOver={(e) => setState({ ...state, isHovered: true })}
      onPointerOut={(e) => setState({ ...state, isHovered: false })}>
      <sphereBufferGeometry args={[0.5, 40, 40]} map={colorMap} />
      <meshStandardMaterial map={colorMap} />
    </mesh>
  )
}



export default function App() {
  return (
    <Canvas camera={{position: [0, 2, 8]}}>
      <Sun position={[0, 0, 0]} />
      <Earth position={[3, 0, 0]} />
      <ambientLight intensity={0.01}/>
      <pointLight position={[0, 0, 0]}/>
      
      <spotLight position={[1.5, 0, 0]} distance={4}/>
      <spotLight position={[-1.5, 0, 0]} distance={4}/>
      <spotLight position={[0, 0, -1.5]} distance={4}/>
      <spotLight position={[0, 0, 1.5]} distance={4}/>
      <spotLight position={[0, 1.5, 0]} distance={4}/>
      <spotLight position={[0, -1.5, 0]} distance={4}/>
    </Canvas>
  )
}

特别是纹理部分是个问题，但我找不到任何问题。

const [colorMap] = useTexture(['Sun_texture.jpg'])
...
<sphereGeometry args={[0.5, 100, 100]} map={colorMap} />
<meshStandardMaterial map={colorMap} transparent={true} emissive={'#444444'} emissiveIntensity={0.3}/>

Answer 1

您需要将 <Earth> 组件放在 <Suspense> 中，因为它需要加载纹理，所以方法是使用悬念等待它加载。

您可以通过执行以下操作指定要在加载时显示的对象

<suspense fallback={<loadingComponent />} >

所以这会给你类似的东西：

import React, { useRef, useState, Suspense } from 'react'
import { Canvas, useFrame, useLoader } from 'react-three-fiber'
import { TextureLoader } from 'three/src/loaders/TextureLoader'
import { useTexture } from "@react-three/drei";

function Sun(props) {
  const [colorMap] = useTexture(['Sun_texture.jpg'])
  const mesh = useRef()
  const [state, setState] = useState({ isHovered: false, isActive: false })
  useFrame((state) => {
    const time = state.clock.getElapsedTime()
    mesh.current.rotation.z = 0
    mesh.current.rotation.x = 0
    mesh.current.rotation.y = time / 5
  })

  return (
    <mesh
      {...props}
      ref={mesh}
      
      scale={[1, 1, 1]}
      onPointerOver={(e) => setState({ ...state, isHovered: true })}
      onPointerOut={(e) => setState({ ...state, isHovered: false })}>
      <sphereGeometry args={[0.5, 100, 100]} map={colorMap} />
      <meshStandardMaterial map={colorMap} transparent={true} emissive={'#444444'} emissiveIntensity={0.3}/>
    </mesh>
  )
}

function Earth(props) {
  const mesh = useRef()
  const [state, setState] = useState({ isHovered: false, isActive: false })
  const [colorMap] = useTexture(['Earth_texture.jpg'])
  useFrame((state) => {
    const time = state.clock.getElapsedTime()
    mesh.current.position.x = 4 * Math.sin(time / 10)
    mesh.current.position.y = 0
    mesh.current.position.z = 4 * Math.cos(time / 10)
    mesh.current.rotation.z = 0
    mesh.current.rotation.x = 0
    mesh.current.rotation.y = time / 2
  })

  return (
    <mesh
      {...props}
      ref={mesh}
      scale={[0.5, 0.5, 0.5]}
      onPointerOver={(e) => setState({ ...state, isHovered: true })}
      onPointerOut={(e) => setState({ ...state, isHovered: false })}>
      <sphereBufferGeometry args={[0.5, 40, 40]} map={colorMap} />
      <meshStandardMaterial map={colorMap} />
    </mesh>
  )
}



export default function App() {
  return (
    <Canvas camera={{position: [0, 2, 8]}}>
      <Sun position={[0, 0, 0]} />
      <Suspense fallback={<Loading />}>
      <Earth position={[3, 0, 0]} />
      </Suspense>
      <ambientLight intensity={0.01}/>
      <pointLight position={[0, 0, 0]}/>
      
      <spotLight position={[1.5, 0, 0]} distance={4}/>
      <spotLight position={[-1.5, 0, 0]} distance={4}/>
      <spotLight position={[0, 0, -1.5]} distance={4}/>
      <spotLight position={[0, 0, 1.5]} distance={4}/>
      <spotLight position={[0, 1.5, 0]} distance={4}/>
      <spotLight position={[0, -1.5, 0]} distance={4}/>
    </Canvas>
  )
}

您可以在 codeSandbox 上找到有关 react-three-fiber 的精彩内容和示例。

https://codesandbox.io/search?refinementList%5Bnpm_dependencies.dependency%5D%5B0%5D=%40react-three%2Ffiber&page=1&configure%5BhitsPerPage%5D=12&query=

如果您需要更高的精度，请告诉我。

使用 React-Three-Fiber

Using React-Three-Fiber

reactjs

react-three-fiber