Input.GetAxisRaw

説明

axisName で識別される仮想軸の平滑化フィルターが適用されていない値を返します

The value will be in the range -1...1 for keyboard and joystick input. Since input is not smoothed, keyboard input will always be either -1, 0 or 1. This is useful if you want to do all smoothing of keyboard input processing yourself.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour
{
    void Update()
    {
        float speed = Input.GetAxisRaw("Horizontal") * Time.deltaTime;
        transform.Rotate(0, speed, 0);
    }
}

The GetAxis page describes in detail what the axisName for GetAxisRaw means. For example the Horizontal axis is managed by Left and Right, and a and d keys. Other Input Axes can be seen in the Edit->Settings->Input window.