三角函数:
概念:用来描述三角形中某个角和对应的三条边的比例关系。
正弦:sin<θ>(sin<theta>)=对边/斜边
余弦:cos<θ>(cos<theta>)=邻边/斜边
正切:tan<θ>(tan<theta>)=对边/邻边
正弦函数曲线:随着θ角度不断增大,sinθ的值的变化周期
余弦函数曲线:正弦函数曲线左移90度
反三角函数:已知比例关系,反推出角度或者弧度。
反正弦:Arcsin(0.5)=30度
反余弦:Arccos
反正切:Arctan
向量的乘法:
向量的点乘:a(ax,ay,az) · b(bx.by.bz)
数学运算:a·b = axbx + ayby + azbz,各分量分别相乘再相加
1、满足乘法交换律
2、结果是标量
几何意义:
a·b = |a| * |b| * cos<a,b>,<a,b>夹角范围0~180度,两个向量夹角越小,相似度越高
a·b = (|a| * cos<a,b>) * |b|,最重要的几何意义就是求投影
1、a向量在b向量方向上投影的长度再乘以b向量的模长
2、当b向量为单位向量的时候,结果就是:a向量在b向量方向上投影的长度
3、当a向量和b向量都是单位向量的时候,结果就是:两个向量的夹角的余弦
敌人的正前方和敌人与自己连线的夹角,小于90度,在敌人前方,大于90度,在敌人后方
API Vector3.Dot(Vector3 lhs,Vector3 rhs),两个向量点乘满足乘法交换律,但叉乘不行
API Vector3.Angle,直接计算两个向量之间的夹角
思考题:入射光线和反射光线不在一个水平线上
using System.Collections;using System.Collections.Generic;using UnityEngine;publicclass EnemyLook : MonoBehaviour
{
public Transform player;
publicfloat result;
publicfloat distance;
// Use this for initializationvoid Start()
{
////向量点乘的数学运算//Vector3 enemy2Player = player.position - transform.position;
//Vector3 enemyForward = transform.forward;
//result = enemy2Player.x * enemyForward.x + enemy2Player.y * enemyForward.y + enemy2Player.z + enemyForward.z;
//把向量变成单位向量Vector3 enemy2Player = (player.position - transform.position).normalized;
Vector3 enemyForward = transform.forward;
//计算两个向量之间的夹角result = Vector3.Dot(enemy2Player, enemyForward);
//计算两个物体之间的距离distance = Vector3.Distance(player.position, transform.position);
//API:计算两个向量之间的夹角
//Vector3.Angle(); }
// Update is called once per framevoid Update()
{
}
privatevoid OnGUI()
{
//if (result > 0)
//{
// GUILayout.Label("在敌人前方");
//}
//else
//{
// GUILayout.Label("在敌人后方");
//}if(result > Mathf.Cos(30* Mathf.Deg2Rad) && distance <5)
{
GUILayout.Label("在扇形范围内:"+ Mathf.Acos(result) * Mathf.Rad2Deg +"度");
}
else {
GUILayout.Label("不在扇形范围内:"+ Mathf.Acos(result) * Mathf.Rad2Deg +"度");
}
}
}
using System.Collections;using System.Collections.Generic;using UnityEngine;publicclass TestTrans : MonoBehaviour {
public Transform Target;
publicfloat distance;
privatefloatSkillDistance =5;//扇形距离privatefloatSkillJiaodu =60;//扇形的角度
// Use this for initializationvoid Start () {
////偶然性编程distance = Vector3.Distance(transform.position, Target.position);//距离Vector3 norVec = transform.rotation * Vector3.forward;
Vector3 temVec = Target.position - transform.position;
Debug.DrawLine(transform.position, norVec, Color.red);//画出技能释放者面对的方向向量Debug.DrawLine(transform.position, Target.position, Color.green);//画出技能释放者与目标点的连线floatjiajiao = Mathf.Acos(Vector3.Dot(norVec.normalized, temVec.normalized)) * Mathf.Rad2Deg;
if(distance <= SkillDistance)
{
if(jiajiao <= SkillJiaodu)
{
Debug.Log("在扇形范围内");
}
else {
Debug.Log("不在扇形范围内");
}
}
}
// Update is called once per framevoid Update () {
}
}
using System.Collections;using System.Collections.Generic;using UnityEngine;publicclass CrystalMove : MonoBehaviour {
//public Transform startTrans;
//public float moveSpeed = 1;
//public float rotSpeed = 1;publicfloatrotateSpeed =30;
//调节上下频率和浮动publicfloatamplitude = 1f;
publicfloatfrequency = 1f;
// Use this for initializationvoid Start () {
}
// Update is called once per framevoid Update () {
// transform.Rotate(Vector3.up, Space.World);
// Vector3 delta = Vector3.up * Mathf.Sin(Time.time) * moveSpeed*0.25F;
// transform.position = startTrans.position + delta;transform.Rotate(Vector3.up * Time.deltaTime * rotateSpeed);
floatsin = Mathf.Sin(Time.time * frequency) * amplitude;
transform.Translate(Vector3.up * sin, Space.World);
}
}
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