Unity向量的点乘用于判断怪物相对于人物的方向
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Vector3_Class_methods : MonoBehaviour {
// 用于演示Vector3的函数
Vector3 Apoint;
Vector3 Bpoint;
Vector3 Cpoint;
public Transform oneObj, twoObj;
public Transform Hero, Monster;
public Transform PointA, PointB;
void Start()
{
Apoint = new Vector3(0, 0, 4);
Bpoint = new Vector3(0, 3, 0);
Cpoint = new Vector3(1, 1, 1);
Debug.Log("(0,0,1)和(0,1,0)两个向量夹角："+Vector3.Angle(Apoint, Bpoint));//求向量夹角
Debug.Log("两个箱子两个向量夹角是（相对点是原点）：" + Vector3.Angle(oneObj.position, twoObj.position));//求向量夹角
#region
Debug.Log("(0,0,1)和(0,1,0)两个向量点乘结果：" + Vector3.Dot(Apoint, Bpoint));//求向量点乘结果
Debug.Log("两个箱子坐标向量点乘结果（相对点是原点）：" + Vector3.Dot(oneObj.position, twoObj.position));//求向量点乘结果
#endregion
}
// Update is called once per frame
void Update() {
//Debug.Log("(0,0,1)和(0,1,0)两个向量点乘结果：" + Vector3.Dot(Apoint, Bpoint));//求向量点乘结果
Debug.Log("两个箱子坐标向量点乘结果（相对点是原点）：" + Vector3.Dot(oneObj.position, twoObj.position));//求向量点乘结果
Debug.DrawLine(Vector3.zero, twoObj.position, Color.red);
Debug.DrawLine(Vector3.zero, oneObj.position, Color.blue);
Relativepos(Hero, Monster);//用于判断物体hero和Monster的前后位置
DrawNormalLine(PointA.position, PointB.position);// 求两个向量的 构成面的法向量
Distance(Apoint, Bpoint);
}
private void DrawNormalLine(Vector3 A, Vector3 B)//求两个向量的 构成面的法向量
{
Vector3 NormalLine= Vector3.Cross(A, B);//求两个向量的 构成面的法向量
Vector3 StartPoint = (A + B) / 2;
Debug.Log(""+NormalLine+ NormalLine.normalized);
Debug.DrawLine(StartPoint, NormalLine, Color.green);
Debug.DrawLine(Vector3.zero, A, Color.blue);
Debug.DrawLine(Vector3.zero, B, Color.blue);
}
private void Relativepos(Transform Hero, Transform Monster)//用DOT【点乘】于判断物体hero和Monster的前后位置
{
Vector3 HeroPos = Hero.TransformDirection(Hero.forward);//从局部坐标系转世界坐标系
Vector3 RelaPosVector = Monster.position - Hero.position;
float Dot = Vector3.Dot(HeroPos, RelaPosVector);
Debug.DrawLine(Hero.position, Monster.position, Color.blue);
if (Dot > 0)
{
Debug.Log("怪物在角色英雄前面");
}
if (Dot == 0)
{
Debug.Log("怪物在角色英雄侧面");
}
if (Dot<0)
{
Debug.Log("怪物在角色英雄后面");
}
}
private void Distance(Vector3 A, Vector3 B)
{
Debug.Log("两个向量的距离"+Vector3.Distance(A,B));
}
}