ArrowPorter.cs

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class ArrowPorter : MonoBehaviour {
  public static ArrowPorter selected;

  [Header("Initialization")]
  public Arrow arrowPrototype;
  public Camera specialCamera;
  public Transform spawns;

  void Update () {
    RaycastHit hit;
    Ray ray = (specialCamera? specialCamera: Camera.main).ScreenPointToRay(Input.mousePosition);

    if (Physics.Raycast(ray, out hit) && hit.collider.GetComponentInParent<ArrowPorter>() == this) {
      if (Input.GetMouseButtonDown(1)) {
        Arrow created = Instantiate(arrowPrototype);
        created.line.SetPosition(0, hit.point + hit.normal * 0.05f);
        created.specialCamera = specialCamera;
        created.transform.parent = spawns;
      }
    }
  }

  void OnMouseEnter () {
    selected = this;
  }

  void OnMouseExit () {
    if (selected == this) {
      selected = null;
    }
  }
}