Three.js 触摸滑动显示线条,触摸结束线条消失
时间: 2024-01-11 14:05:50 浏览: 27
要实现这个效果,需要用到 Three.js 的鼠标/触摸事件和线条材质。以下是一个简单的实现方式:
1. 创建一个 Three.js 场景和相机。
```
var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera( 75, window.innerWidth / window.innerHeight, 0.1, 1000 );
camera.position.z = 5;
```
2. 创建一个网格平面作为背景。
```
var geometry = new THREE.PlaneGeometry( 10, 10, 10 );
var material = new THREE.MeshBasicMaterial( { color: 0x888888 } );
var plane = new THREE.Mesh( geometry, material );
scene.add( plane );
```
3. 创建一个线条材质,并将其应用于一个 Three.js 线条对象。
```
var material = new THREE.LineBasicMaterial( { color: 0xffffff } );
var geometry = new THREE.Geometry();
var line = new THREE.Line( geometry, material );
scene.add( line );
```
4. 监听触摸事件,并在触摸开始时清空线条的顶点数组,设置第一个顶点的位置,并将线条对象加入场景。
```
var isDrawing = false;
document.addEventListener('touchstart', function(event) {
isDrawing = true;
line.geometry.vertices = [];
var x = event.touches[0].clientX / window.innerWidth * 2 - 1;
var y = -(event.touches[0].clientY / window.innerHeight) * 2 + 1;
var z = 0.5;
var vertex = new THREE.Vector3(x, y, z);
line.geometry.vertices.push(vertex);
scene.add(line);
});
```
5. 监听触摸移动事件,并根据触摸位置添加新的线条顶点。
```
document.addEventListener('touchmove', function(event) {
if (isDrawing) {
var x = event.touches[0].clientX / window.innerWidth * 2 - 1;
var y = -(event.touches[0].clientY / window.innerHeight) * 2 + 1;
var z = 0.5;
var vertex = new THREE.Vector3(x, y, z);
line.geometry.vertices.push(vertex);
line.geometry.verticesNeedUpdate = true;
}
});
```
6. 监听触摸结束事件,并在结束时将 isDrawing 标志设置为 false,使线条消失。
```
document.addEventListener('touchend', function(event) {
isDrawing = false;
});
```
这就是一个简单的 Three.js 触摸滑动显示线条,触摸结束线条消失的实现方式。你可以根据自己的需求对其进行调整和优化。