Three.js - RingGeometry 环形几何体
THREE.RingGeometry 创建一个中心有孔的 D 形圆盘。它与圆形几何体非常相似。
innerRadius − 圆的内半径定义中心孔的大小。0 表示无孔。默认值为 0.5。
outerRadius − 圆的外半径定义其大小。默认值为 1。
thetaSegments − 用于创建圆的对角线段数。默认值为 8。段数越多，圆越平滑。
phiSegments − 沿环长度使用的段数。默认值为 8。
thetaStart − 开始绘制圆的位置。此值的范围为 0 到 2 * PI，默认值为 0。
thetaLength − 此属性定义圆完成的程度。默认值为 2 * PI。
const ring = new THREE.RingGeometry( innerRadius, outerRadius, thetaSegments, phiSegments, thetaStart, thetaLength )
示例
查看以下示例。
ring.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="ie=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Three.js - Ring</title>
<style>
* {
margin: 0;
padding: 0;
box-sizing: border-box;
font-family: -applesystem, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu,
Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
}
html,
body {
height: 100vh;
width: 100vw;
}
#threejs-container {
position: block;
width: 100%;
height: 100%;
}
</style>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r128/three.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/dat-gui/0.7.7/dat.gui.js"></script>
</head>
<body>
<div id="threejs-container"></div>
<script type="module">
// Ring geometry
// a simple 2d ring in Three.js
// GUI
const gui = new dat.GUI()
// sizes
let width = window.innerWidth
let height = window.innerHeight
// scene
const scene = new THREE.Scene()
scene.background = new THREE.Color(0x262626)
// camera
const camera = new THREE.PerspectiveCamera(30, width / height, 0.1, 100)
camera.position.set(0, 0, 10)
const camFolder = gui.addFolder('Camera')
camFolder.add(camera.position, 'z').min(10).max(60).step(10)
camFolder.open()
// Light
const ambientLight = new THREE.AmbientLight(0xffffff, 1)
scene.add(ambientLight)
const pointLight = new THREE.PointLight(0xffffff, 0.2)
pointLight.position.x = 2
pointLight.position.y = 3
pointLight.position.z = 4
scene.add(pointLight)
// ring
const geometry = new THREE.RingGeometry()
const material = new THREE.MeshBasicMaterial({
color: 0xffffff,
wireframe: true,
side: THREE.DoubleSide
})
const materialFolder = gui.addFolder('Material')
materialFolder.add(material, 'wireframe')
materialFolder.open()
const ring = new THREE.Mesh(geometry, material)
scene.add(ring)
const ringProps = {
innerRadius: 1,
outerRadius: 5,
thetaSegments: 8,
phiSegments: 8,
thetaStart: 0,
thetaLength: 2 * Math.PI
}
const props = gui.addFolder('Properties')
props
.add(ringProps, 'innerRadius', 1, 50)
.step(1)
.onChange(redraw)
.onFinishChange(() => console.dir(ring.geometry))
props.add(ringProps, 'outerRadius', 1, 50).step(1).onChange(redraw)
props.add(ringProps, 'thetaSegments', 1, 50).step(1).onChange(redraw)
props.add(ringProps, 'phiSegments', 1, 50).step(1).onChange(redraw)
props.add(ringProps, 'thetaStart', 0, 2 * Math.PI).onChange(redraw)
props.add(ringProps, 'thetaLength', 0, 2 * Math.PI).onChange(redraw)
props.open()
function redraw() {
let newGeometry = new THREE.RingGeometry(
ringProps.innerRadius,
ringProps.outerRadius,
ringProps.thetaSegments,
ringProps.phiSegments,
ringProps.thetaStart,
ringProps.thetaLength
)
ring.geometry.dispose()
ring.geometry = newGeometry
}
// responsiveness
window.addEventListener('resize', () => {
width = window.innerWidth
height = window.innerHeight
camera.aspect = width / height
camera.updateProjectionMatrix()
renderer.setSize(window.innerWidth, window.innerHeight)
renderer.render(scene, camera)
})
// renderer
const renderer = new THREE.WebGL1Renderer()
renderer.setSize(width, height)
renderer.setPixelRatio(Math.min(window.devicePixelRatio, 2))
// animation
function animate() {
requestAnimationFrame(animate)
ring.rotation.x += 0.005
ring.rotation.y += 0.01
renderer.render(scene, camera)
}
// rendering the scene
const container = document.querySelector('#threejs-container')
container.append(renderer.domElement)
renderer.render(scene, camera)
animate()
</script>
</body>
</html>
threejs_geometries.html
