Vector3.Dot 点乘

# [Vector3](Vector3.html).Dot 点乘

static function *Dot* (*lhs* : [Vector3](Vector3.html), *rhs* : [Vector3](Vector3.html)) : float

*Description* 描述

Dot Product of two vectors.

两个向量的点乘积。

Returns lhs . rhs.

返回 lhs . rhs。

For [normalized](Vector3.normalized.html) vectors Dot returns 1 if
they point in exactly the same direction; -1 if they point in completely
opposite directions; and a number in between for other cases (e.g. Dot returns
zero if vectors are perpendicular).

对于 [normalized](Vector3.normalized.html) 向量，如果他们指向在完全相同的方向，Dot 返回 1。如果他们指向完全相反的方向，返回-1。对于其他的情况返回一个数（例如：如果是垂直的 Dot 返回 0）。

For vectors of arbitrary length the Dot return values are similar: they get
larger when the angle between vectors decreases.

对于任意长度的向量，Dot 返回值是相同的：当向量之间的角度减小，它们得到更大的值。

* [C#](#)
* [JavaScript](#)

```
using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
	public Transform other;
	void Update() {
		if (typeof(other)) {
			Vector3 forward = transform.TransformDirection(Vector3.forward);
			Vector3 toOther = other.position - transform.position;
			if (Vector3.Dot(forward, toOther) < 0)
				print("The other transform is behind me!");

}
	}
}
```

```
// detects if other transform is behind this object
//检测其他变换是否在这个物体的后面

var other : Transform;
function Update() {
	if (other) {
		var forward = transform.TransformDirection(Vector3.forward);
		var toOther = other.position - transform.position;
		if (Vector3.Dot(forward,toOther) < 0)
			print ("The other transform is behind me!");
	}
}
```