Vector3.Dot 点乘

static function Dot (lhs : Vector3, rhs : Vector3) : float


Dot Product of two vectors.


Returns lhs . rhs.

返回lhs . rhs。

For normalized 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).


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


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

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!");
Page last updated: 2010-12-20