Unity 获取BoxCollider八个点的世界坐标

我们想把场景中的BoxCollider的坐标点导出出来让服务器也能用。虽然BoxCollider自身的大小可以获取出来，但是如果有父对象，并且有坐标的变化那算起来就比较麻烦了。还好unity提供了一个方法，真的很便捷。如下图所示，我用了8个标记点来标记获取到的boxcollider的坐标。旋转、缩放都可以计算出正确的坐标点来。



using UnityEngine;
using System.Collections;

public class Test : MonoBehaviour
{
//8个标志位 ，用来在scene里预览
public Transform[] points;
//需要提取Boxcollier顶点的对象
public BoxCollider cube;

void Start()
{
//父节只能调节位置， 不能调节旋转和缩放。
Transform parent = cube.transform.parent;
while(parent!=null)
{
parent.localRotation = Quaternion.Euler(Vector3.zero);
parent.localScale = Vector3.one;
parent = parent.parent;
}
}

void Update()
{
Vector3 [] veces = GetBoxColliderVertexPositions(cube);
for(int i =0; i< veces.Length; i++)
{
points[i].transform.position = veces[i];
}
}

Vector3[] GetBoxColliderVertexPositions (BoxCollider boxcollider)
{
var vertices = new Vector3[8];
//下面4个点
vertices[0] = boxcollider.transform.TransformPoint(boxcollider.center + new Vector3(boxcollider.size.x, -boxcollider.size.y, boxcollider.size.z) * 0.5f);
vertices[1] = boxcollider.transform.TransformPoint( boxcollider.center + new Vector3(-boxcollider.size.x, -boxcollider.size.y, boxcollider.size.z) * 0.5f);
vertices[2] = boxcollider.transform.TransformPoint( boxcollider.center + new Vector3(-boxcollider.size.x, -boxcollider.size.y, -boxcollider.size.z) * 0.5f);
vertices[3] = boxcollider.transform.TransformPoint(boxcollider.center + new Vector3(boxcollider.size.x, -boxcollider.size.y, -boxcollider.size.z) * 0.5f);
//上面4个点
vertices[4] = boxcollider.transform.TransformPoint(boxcollider.center + new Vector3(boxcollider.size.x, boxcollider.size.y, boxcollider.size.z) * 0.5f);
vertices[5] = boxcollider.transform.TransformPoint( boxcollider.center + new Vector3(-boxcollider.size.x, boxcollider.size.y, boxcollider.size.z) * 0.5f);
vertices[6] = boxcollider.transform.TransformPoint( boxcollider.center + new Vector3(-boxcollider.size.x, boxcollider.size.y, -boxcollider.size.z) * 0.5f);
vertices[7] = boxcollider.transform.TransformPoint(boxcollider.center + new Vector3(boxcollider.size.x, boxcollider.size.y, -boxcollider.size.z) * 0.5f);

return vertices;
}
}