核心是使用LatheGeometry将一个2D的线扫描成3D物体
function createObj() {
// 创建的单个粒子的尺寸为（radius * 2, height + radius * 2, radius * 2）
const radius = 4;
const height = 192;
itemHeight = radius * 2 + height;
// 存放样条曲线的点集
const points = [];
//上半部分四分之一圆弧
for (let i = Math.PI / 2; i > 0; i -= 0.3) {
points.push(
new THREE.Vector2(
Math.cos(i) * radius,
Math.sin(i) * radius + height / 2
)
);
}
//中间直线
for (let i = height / 2; i > -height / 2; i -= height) {
points.push(new THREE.Vector2(radius, i));
}
//下半部分四分之一圆弧
for (let i = 0; i <= Math.PI / 2; i += 0.3) {
points.push(
new THREE.Vector2(
Math.cos(i) * radius,
-Math.sin(i) * radius - height / 2
)
);
}
// 补充一个点，去掉底部的小洞
points.push(new THREE.Vector2(0, -radius - height / 2));
console.log(points);
const geometry = new THREE.LatheGeometry(points);
const pngec = textureLoader.load(pngUrl);
// 围绕中心点旋转180度
// pngec.center = new THREE.Vector2(0.5, 0.5);
// pngec.rotation = Math.PI;
// pngec.mapping = THREE.UVMapping;
const material = new THREE.MeshBasicMaterial({
transparent: true,
opacity: 0.6,
vertexColors: false,
map: pngec,
blending: THREE.AdditiveBlending,
color: new THREE.Color(0xffffff),
});
const mesh = new THREE.Mesh(geometry, material);
return mesh;
}
