移動システムの設計は、ゲームに独自の感覚を与えるための重要な部分であり、必要な機能はあなたのゲームに特有のものです。Rigidbodyを3Dで動かす方法の例をお見せしますが、あなたが望む動きを実現するには、それを微調整する必要があります。
```csharp
using UnityEngine;

public class FirstPersonMovement : MonoBehaviour {
	// Rigidbody component used to move the character
	public Rigidbody rb;

	// Use this function to move the character in first-person mode
	void Update() {
		float horizontal = Input.GetAxis("Horizontal");
		float vertical = Input.GetAxis("Vertical");

		// Calculate new position based on input
		Vector3 newPosition = new Vector3(horizontal, 0, vertical);

		// Set the new position of the character’s Rigidbody
		rb.transform.position = newPosition;
	}
}
```
このスクリプトでは、Input.GetAxis()関数を使用してユーザーから水平方向と垂直方向の入力を取得し、newPosition変数を使用してキャラクターのRigidbodyの新しい位置を設定します。rbコンポーネントは動かしたいRigidbodyコンポーネントのインスタンスで、transformプロパティはキャラクターの位置です。最後に、Update()関数をフレームごとに呼び出して、キャラクタの位置を更新します。
Designing a movement system is a key part of giving your game its own unique feel, and the features it needs will be specific to your game. I can show you an example of how to move a Rigidbody in 3D, but you will need to tweak it to achieve the type of movement you want.
```csharp
using UnityEngine;

public class FirstPersonMovement : MonoBehaviour {
	// Rigidbody component used to move the character
	public Rigidbody rb;

	// Use this function to move the character in first-person mode
	void Update() {
		float horizontal = Input.GetAxis("Horizontal");
		float vertical = Input.GetAxis("Vertical");

		// Calculate new position based on input
		Vector3 newPosition = new Vector3(horizontal, 0, vertical);

		// Set the new position of the character’s Rigidbody
		rb.transform.position = newPosition;
	}
}
```
This script uses the Input.GetAxis() function to get the horizontal and vertical input from the user, and uses the newPosition variable to set the new position of the character’s Rigidbody. The rb component is the instance of the Rigidbody component that we want to move, and the transform property is the location of the character. Finally, the Update() function is called every frame to update the character’s position.