【Unity】桜を咲かせてみた【初心者向け】 ref: http://qiita.com/kuuki_yomenaio/items/ea77a12834296645bc92

CharacterMove.cs

using UnityEngine;
using System.Collections;

public class CharacterMove : MonoBehaviour {

    float forwardSpeed = 3.0f;
    float backwardSpeed = 1.0f;
    float rotateSpeed = 10.0f;
    CharacterController characterController;
    void Start () {
        characterController = GetComponent<CharacterController>();
    }

    void Update () {
        float v = Input.GetAxis("Vertical");
        float h = Input.GetAxis("Horizontal");

        Vector3 velocity = new Vector3(0, 0, v);
        velocity = transform.TransformDirection(velocity);
        if (v > 0) {
            velocity *= forwardSpeed;
        } else if (v < 0) {
            velocity *= backwardSpeed;
        }
        characterController.Move(velocity * Time.deltaTime);
        transform.Rotate(0, h * rotateSpeed, 0);
    }
}

SakuraCreater.cs

using UnityEngine;
using System.Collections;

public class SakuraCreater : MonoBehaviour {

    public GameObject flower;
    public ParticleSystem sakuraSakuEffect;
    public ParticleSystem sakuraTiruEffect;
    // Use this for initialization
    void Start () {
        sakuraSakuEffect.Stop();
        sakuraTiruEffect.Stop();
    }

    /// <summary>
    /// BoxColliderのIsTriggerをONにしている際に、
    /// オブジェクトが範囲に入った際に呼ばれるイベント
    /// </summary>
    /// <param name="col">Col.</param>
    void OnTriggerEnter(Collider col){

        for(int i = 0 ; i < 5 ; i++){
            createSakura();
        }

        sakuraSakuEffect.Play();
        sakuraTiruEffect.Play();
    }

    /// <summary>
    /// 桜の花を一つ作成します。
    /// </summary>
    /// <returns>The sakura.</returns>
    private void createSakura(){
        Vector3 pos = this.gameObject.transform.position;

        float x = Random.Range(-1.0f , 1.0f);
        float y = Random.Range(1.0f , 2.0f);
        float z = Random.Range(-1.0f , 1.0f);

        pos.x += x;
        pos.y += y;
        pos.z += z;

        GameObject obj = Instantiate(flower , pos , Quaternion.identity) as GameObject;
        obj.transform.SetParent(this.gameObject.transform);
    }
}