Unity3D研究院之主角面朝方向一定区域内对象角度计算

偏执的太偏执、 2022-03-31 03:49 238阅读 0赞

**在上代码之前请大家跟我先做几个简单的练习题，角度向量的计算一定要学会，不然后面的东西会很难懂。**

**1.已知3D坐标，和一个旋转角度，以及一段距离，求目标点的3D坐标。**

**已知当前点为Target，目标点沿着Target的Y轴旋转30度，沿着Target的X轴延伸10米求目标点的3D坐标？**

[view source][]

<table> 
 <tbody> 
  <tr> 
   <td><code>01</code></td> 
   <td><code>using</code> <code> UnityEngine; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>02</code></td> 
   <td><code>using</code> <code> System.Collections; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>04</code></td> 
   <td><code>public</code> <code> class</code> <code>Test : MonoBehaviour </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>07</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>public</code> <code>Transform Target; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>09</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>void</code> <code>LateUpdate () </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>11</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Quaternion rotation = Quaternion.Euler(0f,30f,0f) * Target.rotation; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>12</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Vector3&nbsp; newPos = rotation * </code><code>new</code> <code>Vector3(10f,0f,0f); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>13</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.DrawLine(newPos,Vector3.zero,Color.red); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>14</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.Log(</code><code>"newpos "</code> <code>+ newPos +</code><code>" nowpos "</code> <code>+ Target.position + </code><code>" distance "</code> <code>+ Vector3.Distance(newPos,Target.position)); </code></td> 
  </tr> 
 </tbody> 
</table>

** 输出结果 ：新坐标 (8.7, 0.0, -5.0) 当前坐标 (0.0, 0.0, 0.0)两点之间的距离 10。**

** 2.已知3D模型的角度求它的向量。**

**已知3D模型Target，Y轴旋转30度后向前平移。**

[view source][]

<table> 
 <tbody> 
  <tr> 
   <td><code>01</code></td> 
   <td><code>using</code> <code> UnityEngine; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>02</code></td> 
   <td><code>using</code> <code> System.Collections; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>04</code></td> 
   <td><code>public</code> <code> class</code> <code>Test : MonoBehaviour </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>07</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>public</code> <code>Transform Target; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>09</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>void</code> <code>LateUpdate () </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>12</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>if</code><code>(Input.GetMouseButton(0)) </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>14</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Quaternion rotation = Quaternion.Euler(0f,30f,0f) * Target.rotation; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>15</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Vector3&nbsp; newPos = rotation * Vector3.forward; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>16</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Target.Translate(newPos.x,newPos.y,newPos.z); </code></td> 
  </tr> 
 </tbody> 
</table>

** 3.已知一个目标点，让模型朝着这个目标点移动。**

**这是一个比较简单的例子，大家应该都能看明白。**

[view source][]

<table> 
 <tbody> 
  <tr> 
   <td><code>1</code></td> 
   <td><code>Target.transform.LookAt(</code><code>new</code> <code>Vector3 (100f,200f,300f)); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>2</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Target.Translate(Vector3.forward);</code></td> 
  </tr> 
 </tbody> 
</table>

**这里我要说的就是Vector3.forward ，它等价与 new Vector3(0,0,1)；它并不是一个坐标，它是一个标准向量，方向是沿着Z轴向前。这样平移一次的距离就是1米， 如果Vector3.forward \* 100那么一次平移的距离就是100米。 **

**在看看下面这段代码**

[view source][]

<table> 
 <tbody> 
  <tr> 
   <td><code>1</code></td> 
   <td><code>Vector3 vecn = (TargetCube.position - Target.position).normalized; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>2</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Target.Translate(vecn *0.1f);</code></td> 
  </tr> 
 </tbody> 
</table>

** 用向量减去一个向量求出它们的差值，normalized 是格式化向量，意思是把它们之间向量格式化到1米内。这样就可以更加精确的计算一次平移的距离了 vecn \*0.1f 就标示一次平移1分米，蛤蛤。**

** 向量不仅可以进行X Y Z轴的移动，同样可以进行旋转 ，下面这段代码就是让向量沿着Y轴旋转30度。**

[view source][]

<table> 
 <tbody> 
  <tr> 
   <td><code>1</code></td> 
   <td><code>Vector3 vecn = (TargetCube.position - Target.position).normalized; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>2</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>vecn = Quaternion.Euler(0f,30f,0f) * vecn; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>3</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Target.Translate(vecn *0.1f);</code></td> 
  </tr> 
 </tbody> 
</table>

**如果上述三道简单的练习题 你都能了然于心的话，那么本文最大的难题我相信也不会是什么难事，继续阅读吧。**

**假设我们需要计算主角面前5米内所有的对象时。以主角为圆心计算面前5米外的一个点，为了让大家看清楚我现将这条线绘制出来。**

[view source][]

<table> 
 <tbody> 
  <tr> 
   <td><code>1</code></td> 
   <td><code>private</code> <code> float</code> <code>distance = 5f; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>2</code></td> 
   <td><code>void</code> <code> Update ()&nbsp; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>4</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Quaternion r= transform.rotation; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>5</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Vector3 f0 =&nbsp; (transform.position&nbsp; + (r *Vector3.forward) * distance); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>6</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.DrawLine(transform.position,f0,Color.red); </code></td> 
  </tr> 
 </tbody> 
</table>

**如下图所，我们已经将这两个点计算出来了。此时你可以动态的编辑主角Y轴的坐标，这个点永远都是沿着主角当前角度面前5米以外的点。**

[![屏幕快照 2013-01-29 下午8.13.32][2013-01-29 _8.13.32]][2013-01-29 _8.13.32]

**接下来，我们需要计算主角面前的一个发散性的角度。假设主角看到的是向左30度，向右30度在这个区域。**

[view source][]

<table> 
 <tbody> 
  <tr> 
   <td><code>01</code></td> 
   <td><code>private</code> <code> float</code> <code>distance = 5f; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>02</code></td> 
   <td><code>void</code> <code> Update ()&nbsp; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>04</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Quaternion r= transform.rotation; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>05</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Vector3 f0 =&nbsp; (transform.position&nbsp; + (r *Vector3.forward) * distance); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>06</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.DrawLine(transform.position,f0,Color.red); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>07</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Quaternion r0= Quaternion.Euler(transform.rotation.eulerAngles.x,transform.rotation.eulerAngles.y - 30f,transform.rotation.eulerAngles.z); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>08</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Quaternion r1= Quaternion.Euler(transform.rotation.eulerAngles.x,transform.rotation.eulerAngles.y + 30f,transform.rotation.eulerAngles.z); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>09</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Vector3 f1 =&nbsp; (transform.position&nbsp; + (r0 *Vector3.forward) * distance); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>10</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Vector3 f2 =&nbsp; (transform.position&nbsp; + (r1 *Vector3.forward) * distance); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>11</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.DrawLine(transform.position,f1,Color.red); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>12</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.DrawLine(transform.position,f2,Color.red); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>13</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.DrawLine(f0,f1,Color.red); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>14</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.DrawLine(f0,f2,Color.red); </code></td> 
  </tr> 
 </tbody> 
</table>

**如下图所示，这时主角面前的区域就计算出来了。看起来就是两个三角形之间的区域。**

[![屏幕快照 2013-01-29 下午8.21.47][2013-01-29 _8.21.47]][2013-01-29 _8.21.47]

**最后就是简单的套用公式，计算一个点是否在三角形内，在本文中就是计算敌人的点是否在面前的这两个三角形内。**

[view source][]

<table> 
 <tbody> 
  <tr> 
   <td><code>01</code></td> 
   <td><code>using</code> <code> UnityEngine; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>02</code></td> 
   <td><code>using</code> <code> System.Collections; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>04</code></td> 
   <td><code>public</code> <code> class</code> <code>MyTest : MonoBehaviour { </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>06</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>public</code> <code>Transform cube; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>08</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>private</code> <code>float</code> <code>distance = 5f; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>09</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>void</code> <code>Update ()&nbsp; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>11</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Quaternion r= transform.rotation; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>12</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Vector3 f0 =&nbsp; (transform.position&nbsp; + (r *Vector3.forward) * distance); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>13</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.DrawLine(transform.position,f0,Color.red); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>15</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Quaternion r0= Quaternion.Euler(transform.rotation.eulerAngles.x,transform.rotation.eulerAngles.y - 30f,transform.rotation.eulerAngles.z); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>16</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Quaternion r1= Quaternion.Euler(transform.rotation.eulerAngles.x,transform.rotation.eulerAngles.y + 30f,transform.rotation.eulerAngles.z); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>18</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Vector3 f1 =&nbsp; (transform.position&nbsp; + (r0 *Vector3.forward) * distance); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>19</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Vector3 f2 =&nbsp; (transform.position&nbsp; + (r1 *Vector3.forward) * distance); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>21</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.DrawLine(transform.position,f1,Color.red); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>22</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.DrawLine(transform.position,f2,Color.red); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>24</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.DrawLine(f0,f1,Color.red); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>25</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.DrawLine(f0,f2,Color.red); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>27</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Vector3 point = cube.position; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>29</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>if</code><code>(isINTriangle(point,transform.position,f1,f0) || isINTriangle(point,transform.position,f2,f0) ) </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>31</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.Log(</code><code>"cube in this !!!"</code><code>); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>34</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.Log(</code><code>"cube not in this !!!"</code><code>); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>39</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>private</code>&nbsp; <code>float</code> <code>triangleArea(</code><code>float</code> <code>v0x,</code><code>float</code> <code> v0y,</code><code>float</code> <code>v1x,</code><code>float</code> <code>v1y,</code><code>float</code> <code> v2x,</code><code>float</code> <code>v2y)&nbsp; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>41</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>return</code> <code>Mathf.Abs((v0x * v1y + v1x * v2y + v2x * v0y </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>45</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>bool</code> <code>isINTriangle(Vector3 point,Vector3 v0,Vector3 v1,Vector3 v2) </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>47</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>x = point.x; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>48</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>y = point.z; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>50</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>v0x = v0.x; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>51</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>v0y = v0.z; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>53</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>v1x = v1.x; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>54</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>v1y = v1.z; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>56</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>v2x = v2.x; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>57</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>v2y = v2.z; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>59</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>t = triangleArea(v0x,v0y,v1x,v1y,v2x,v2y); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>60</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>a = triangleArea(v0x,v0y,v1x,v1y,x,y) + triangleArea(v0x,v0y,x,y,v2x,v2y) + triangleArea(x,y,v1x,v1y,v2x,v2y); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>62</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>if</code> <code>(Mathf.Abs(t - a) &lt;= 0.01f)&nbsp; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>64</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>return</code> <code>true</code><code>; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>67</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>return</code> <code>false</code><code>; </code></td> 
  </tr> 
 </tbody> 
</table>

**如下图所示，如果箱子对象是主角的视野中就会检测到。 **

[![屏幕快照 2013-01-29 下午9.43.41][2013-01-29 _9.43.41]][2013-01-29 _9.43.41]

**注意，上图中我的视野选择了两个三角形，如果你需要视野目标点是椭圆形的话，那么可以多设置一些三角形。但是这样就会非常消耗效率，我觉得这里完全可以使用1个三角形，，只是正对的目标点会出现一些偏差，影响其实并不会很大。如下图所示**

[![屏幕快照 2013-01-29 下午9.50.11][2013-01-29 _9.50.11]][2013-01-29 _9.50.11]

**代码简单的修改一下即可。**

[view source][]

<table> 
 <tbody> 
  <tr> 
   <td><code>01</code></td> 
   <td><code>using</code> <code> UnityEngine; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>02</code></td> 
   <td><code>using</code> <code> System.Collections; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>04</code></td> 
   <td><code>public</code> <code> class</code> <code>MyTest : MonoBehaviour { </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>06</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>public</code> <code>Transform cube; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>09</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>void</code> <code>Update ()&nbsp; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>23</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.DrawLine(f1,f2,Color.red); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>25</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Vector3 point = cube.position; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>27</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>if</code><code>(isINTriangle(point,transform.position,f1,f2)) </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>29</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.Log(</code><code>"cube in this !!!"</code><code>); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>32</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.Log(</code><code>"cube not in this !!!"</code><code>); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>37</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>private</code>&nbsp; <code>float</code> <code>triangleArea(</code><code>float</code> <code>v0x,</code><code>float</code> <code> v0y,</code><code>float</code> <code>v1x,</code><code>float</code> <code>v1y,</code><code>float</code> <code> v2x,</code><code>float</code> <code>v2y)&nbsp; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>39</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>return</code> <code>Mathf.Abs((v0x * v1y + v1x * v2y + v2x * v0y </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>43</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>bool</code> <code>isINTriangle(Vector3 point,Vector3 v0,Vector3 v1,Vector3 v2) </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>45</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>x = point.x; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>46</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>y = point.z; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>48</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>v0x = v0.x; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>49</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>v0y = v0.z; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>51</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>v1x = v1.x; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>52</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>v1y = v1.z; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>54</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>v2x = v2.x; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>55</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>v2y = v2.z; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>57</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>t = triangleArea(v0x,v0y,v1x,v1y,v2x,v2y); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>58</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>a = triangleArea(v0x,v0y,v1x,v1y,x,y) + triangleArea(v0x,v0y,x,y,v2x,v2y) + triangleArea(x,y,v1x,v1y,v2x,v2y); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>60</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>if</code> <code>(Mathf.Abs(t - a) &lt;= 0.01f)&nbsp; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>62</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>return</code> <code>true</code><code>; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>65</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>return</code> <code>false</code><code>; </code></td> 
  </tr> 
 </tbody> 
</table>

**上面我们介绍了三角形判断，当然也可以通过矩形来判断是否相交。。**

[![屏幕快照 2013-01-30 上午10.59.03][2013-01-30 _10.59.03]][2013-01-30 _10.59.03]

**代码：**

[view source][]

<table> 
 <tbody> 
  <tr> 
   <td><code>01</code></td> 
   <td><code>using</code> <code> UnityEngine; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>02</code></td> 
   <td><code>using</code> <code> System.Collections; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>04</code></td> 
   <td><code>public</code> <code> class</code> <code>MyTest : MonoBehaviour { </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>06</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>public</code> <code>Transform cube; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>09</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>void</code> <code>Update ()&nbsp; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>12</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Vector3 left =&nbsp; (transform.position&nbsp; + (r *Vector3.left) * distance); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>13</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.DrawLine(transform.position,left,Color.red); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>15</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Vector3 right =&nbsp; (transform.position&nbsp; + (r *Vector3.right) * distance); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>16</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.DrawLine(transform.position,right,Color.red); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>18</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Vector3 leftEnd = (left&nbsp; + (r *Vector3.forward) * distance); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>19</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.DrawLine(left,leftEnd,Color.red); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>21</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Vector3 rightEnd = (right&nbsp; + (r *Vector3.forward) * distance); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>22</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.DrawLine(right,rightEnd,Color.red); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>24</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.DrawLine(leftEnd,rightEnd,Color.red); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>26</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Vector3 point = cube.position; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>28</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>if</code><code>(isINRect(point,leftEnd,rightEnd,right,left)) </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>30</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.Log(</code><code>"cube in this !!!"</code><code>); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>33</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>Debug.Log(</code><code>"cube not in this !!!"</code><code>); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>38</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>private</code> <code>float</code> <code>Multiply(</code><code>float</code> <code>p1x , </code><code>float</code> <code>p1y, </code><code>float</code> <code> p2x,</code><code>float</code> <code>p2y, </code><code>float</code> <code>p0x,</code><code>float</code> <code>p0y) </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>40</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>return</code> <code>((p1x - p0x) * (p2y - p0y) - (p2x - p0x) * (p1y - p0y)); </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>43</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>bool</code> <code>isINRect(Vector3 point,Vector3 v0,Vector3 v1,Vector3 v2,Vector3 v3) </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>57</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>v3x = v3.x; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>58</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>float</code> <code>v3y = v3.z; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>60</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>if</code> <code>(Multiply(x,y, v0x,v0y, v1x,v1y) * Multiply(x,y, v3x,v3y, v2x,v2y) &lt;= 0 &amp;&amp; Multiply(x,y, v3x,v3y, v0x,v0y) * Multiply(x,y, v2x,v2y, v1x,v1y) &lt;= 0) </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>61</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>return</code> <code>true</code><code>; </code></td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td><code>63</code></td> 
   <td><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>return</code> <code>false</code><code>; </code></td> 
  </tr> 
 </tbody> 
</table>

[view source]: http://www.xuanyusong.com/archives/1977#viewSource
[2013-01-29 _8.13.32]: /images/20220331/b37786b26f4c48d49a47c791cc8d7906.png
[2013-01-29 _8.21.47]: /images/20220331/62d398c354434f36ba1a4c398ca78c4b.png
[2013-01-29 _9.43.41]: /images/20220331/3e9054b4418e431b9b1490297a40a615.png
[2013-01-29 _9.50.11]: /images/20220331/a34d71f95bdd4823b411e58b31a3c381.png
[2013-01-30 _10.59.03]: /images/20220331/d72b4a7dde004dd8a89985a953e2d3c3.png