碰撞检测

three提供两种碰撞检测
1.【射线检测【相机视线内是一条直线，这条线触碰到的物体会被检测到】】
========一般可以设置一下射线发射的位置 实时更新位置会比较准=====
let dir = new Vector3(0, 1, 0);
doc.raycaster.set(pos, dir);
//pos是发射起点 dir是另一个点

========一般可以设置一下射线发射的位置 实时更新位置会比较准=====
let worldScene = new THREE.Scene()
let cameraPos = new THREE.Camera.position();
var raycaster = new THREE.Raycaster();//射线检测
var mouse = new THREE.Vector2()
raycaster.setFromCamera( mouse, camera );//设置射线
function onMouseClick(event){
//将鼠标点击位置的屏幕坐标转换成threejs中的标准坐标
mouse.x = (event.clientX/window.innerWidth)2-1
mouse.y = -((event.clientY/window.innerHeight)2-1)
//console.log("mouse:"+mouse.x+","+mouse.y)
// 通过鼠标点的位置和当前相机的矩阵计算出raycaster
raycaster.setFromCamera( mouse, camera );

            // 获取raycaster直线和所有模型相交的数组集合
            var intersects = raycaster.intersectObjects( worldScene.children,true);
            console.log(intersects,"模型集合");
            //将所有的相交的模型的颜色设置为红色
            for ( var i = 0; i < intersects.length; i++ ) {
                intersects[ i ].object.material.color.set( 0xff0000 );
            }
        }

===========================================================================
2.八叉树检测
首先要引入
import {Octree} from './jsm/math/Octree.js'
import {Capsule} from './jsm/math/Capsule.js'
可以在https://threejs.org/examples/games_fps.html 这个地址看例子
let worldOctree = new Octree({
undeferred: true,
depthMax: Infinity,
objectsThreshold: 8,
overlapPct: 0.15
});
let a1 = window.ThreeObj.doc.scene.children[3].position;//一个元素的Vector3坐标 （3维坐标 position）
let a2 = window.ThreeObj.doc.scene.children[4].position;//一个元素的Vector3坐标 （3维坐标 position）
window.ThreeObj.doc.scene.children[4].position.y-=0.02;
const playerCollider2 = new Capsule( a1, a2, 0.0000035 );
console.log("检测对象==",playerCollider2)
const result2 = worldOctree.capsuleIntersect( playerCollider2 );
console.log("当前场景",result2.depth)
当获取不到result2.depth的值时候说明碰撞了