Unityで足音を鳴らすためのスクリプト

FootStepDetector.cs

using UnityEngine;
using System;
using System.Collections;

/// <summary>
/// 足の接地を感知して音を鳴らす
/// </summary>
public class FootStepDetector : MonoBehaviour {

	public FootStepSounds footStepSounds;

	private AudioSource aSource;
	// 足音の最短間隔
	private const float PLAY_INTERVAL_MIN_SEC = 0.4f;
	// 最後に足音鳴らした時刻
	private DateTime lastStepTime;

	#region unity

	void Start ()
	{
		aSource = gameObject.GetComponent<AudioSource> ();
		lastStepTime = DateTime.Now;
	}

	#endregion

	void OnTriggerEnter (Collider col)
	{
		if ((DateTime.Now - lastStepTime).TotalSeconds < PLAY_INTERVAL_MIN_SEC) {
			// タップダンス的な足音連打事故を防ぐ
			return;
		}

		FootStepSounds.StepInfo info = footStepSounds.stepInfos.Find ((i) => i.groundTag == col.gameObject.tag);
		if (info.HasValue()) {
			aSource.clip = info.GetClipRandomely ();
			aSource.Play ();
			lastStepTime = DateTime.Now;
		}
	}
}

FootStepSounds.cs

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

/// <summary>
/// 足音音源を管理
/// </summary>
public class FootStepSounds : MonoBehaviour
{
	/// <summary>
	/// 地面と音の対応情報
	/// </summary>
	[Serializable]
	public struct StepInfo
	{
		// 地面タグ
		public string groundTag;
		// 地面に対応した音
		public List<AudioClip> clips;

		public bool HasValue(){
			return !string.IsNullOrEmpty (groundTag) && clips != null && clips.Count > 0;
		}

		public AudioClip GetClipRandomely(){
			return clips [UnityEngine.Random.Range (0, clips.Count)];
		}
	}

	public List<StepInfo> stepInfos;
}