Vector3.Dot

Description

2つのベクトルの内積

内積は2つのベクトルを乗算し、 2つのベクトル間の角度の余弦を乗算したベクトルの大きさと同じfloat値です。 ２つのベクトルが全く同じ方向を指している場合、正規化されたベクトルの内積は1を返します。 反対方向を向く場合は-1を返します。またベクトルが垂直である場合0を返します。

	// 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!");
		}
	}

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    public Transform other;
    void Update() {
        if (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!");
            
        }
    }
}

import UnityEngine
import System.Collections

public class ExampleClass(MonoBehaviour):

	public other as Transform

	def Update() as void:
		if other:
			forward as Vector3 = transform.TransformDirection(Vector3.forward)
			toOther as Vector3 = (other.position - transform.position)
			if Vector3.Dot(forward, toOther) < 0:
				print('The other transform is behind me!')