从射线原点到撞击点的距离。
using UnityEngine;
using System.Collections;
public class ExampleClass : MonoBehaviour
{
public Vector2 direction;
void Update()
{
//Cast a ray in the direction specified in the inspector.
RaycastHit2D hit = Physics2D.Raycast(this.gameObject.transform.position, direction);
//If something was hit.
if (hit.collider != null)
{
//If the object hit is less than or equal to 6 units away from this object.
if (hit.distance <= 6.0f)
{
Debug.Log("Enemy In Range!");
}
}
}
}