CharactorControl.cs

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

public class CharacterControl : MonoBehaviour {

	public bool isGround = false;
	[HideInInspector]public Rigidbody rb;

	private float height = 0f;
	private bool grounded = false;
	private Vector3 preDirection;

	private void Start () {
		Init ();
		getHeight ();
	}

	private void Update () {
		getGrounded ();
	}

	private void Init () {
		rb = gameObject.GetComponent<Rigidbody> ();
		if (rb == null) {
			rb = gameObject.AddComponent<Rigidbody> ();
		}
	}

	private void getGrounded () {
		RaycastHit hit;
		if (Physics.Raycast (transform.position, -Vector3.up, out hit)) {
			if (hit.distance - height < 0.1) {
				if (grounded) {
					isGround = true;
				}
			} else {
				isGround = false;
			}
		}
	}

	private void getHeight () {
		height = transform.localScale.y;
	}

	void OnCollisionEnter (Collision col) {
		grounded = true;
	}

	public void Move (Vector3 v, Vector3 d) {
		rb.velocity = v;
		if (v != Vector3.zero) {
			transform.LookAt (transform.position + d);
		}
	}
}