3

考虑toLinePath功能：

const toLinePath = (arrayOfPoints, color = 0x000000) => {
  const path = new THREE.Path();
  const firstPoint = arrayOfPoints[0];

  path.moveTo(firstPoint.x, firstPoint.y, firstPoint.z);
  arrayOfPoints.forEach(point => path.lineTo(point.x, point.y, point.z));
  path.closePath();

  const points = path.getPoints();
  const geometry = new THREE.BufferGeometry().setFromPoints(points);
  const material = new THREE.LineBasicMaterial({ color });
  const line = new THREE.Line(geometry, material);
  return line;
};

我想使用react-three-fiber并尝试这样的方法重新创建它：

import React from 'react'
import * as THREE from 'three'
import ReactDOM from 'react-dom'
import { Canvas } from 'react-three-fiber'

function LinePath(props) {
  const vertices = React.useMemo(() => {
    const path = new THREE.Path()
    const firstPoint = props.vertices[0]

    path.moveTo(firstPoint.x, firstPoint.y, firstPoint.z)
    props.vertices.forEach(point => path.lineTo(point.x, point.y, point.z))
    path.closePath()

    return path.getPoints()
  }, [props.vertices])

  return (
    <line>
      <bufferGeometry attach="geometry" setFromPoints={vertices} />
      <lineBasicMaterial attach="material" color="black" />
    </line>
  )
}


ReactDOM.render(
  <Canvas>
    <LinePath vertices={[new THREE.Vector3(0, 0, 0), new THREE.Vector3(2, 2, 0), new THREE.Vector3(-2, 2, 0)]} />
  </Canvas>,
  document.getElementById('root')
)

但是根本没有输出/错误。我想我完全误解了react-three-fibers API。我在这里做错了什么？谢谢，这是沙盒

4

1 回答 1

8

所以我真的想通了。我正在寻找的是useUpdate钩子，它允许我们调用任何给定的方法ref。所以这就是需要做的：

import { Canvas, useUpdate } from 'react-three-fiber'

function LinePath(props) {
  const vertices = ...

  const ref = useUpdate(geometry => {
    geometry.setFromPoints(vertices)
  }, [])

  return (
    <line>
      <bufferGeometry attach="geometry" ref={ref} />
      ...
    </line>
  )
}
于 2019-09-19T12:16:49.397 回答