画圆:
var radius = 40,
segments = 64,
material = new THREE.LineBasicMaterial({ color: 0x0000ff }),
geometry = new THREE.CircleGeometry(radius, segments);
???????// Remove center vertex
???????geometry.vertices.shift();
???????this.scene.add(new THREE.Line(geometry, material));
使用THREE.Line会导致最后一点和第一点未链接,可用
this.scene.add(new THREE.LineLoop(geometry, material));
画圆也可用(该方法可自行设置画圆弧)
let points = [],
length = 100,
circle = 40;
for (let i = 0; i <= length; i++) {
points.push(new THREE.Vector2(circle * Math.cos(Math.PI * 2 * i / length), circle * Math.sin(Math.PI * 2 * i / length)))
}
let shape = new THREE.Shape(points);
let arcGeometry = shape.makeGeometry()
let arcMaterial = new THREE.LineBasicMaterial({ color: 0x38d3f5 });
let arc = new THREE.Line(arcGeometry, arcMaterial);
this.scene.add(arc)
注:该方法画圆最后无法闭合
threejs 画二维圆(圆弧)
原文地址：https://www.cnblogs.com/brainworld/p/8297995.html