Unityで真上からのカメラで位置のクランプ

Clamp.cs

	void Clamp() {
		Vector3 posZToY = position;
		posZToY.y = position.z;
		Vector3 posInScreen = Camera.main.WorldToViewportPoint(posZToY);
		Vector3 pos = position;
		posInScreen.x = Mathf.Clamp (posInScreen.x, 0, 1);
		posInScreen.y = Mathf.Clamp (posInScreen.y, 0, 1);
		Vector3 _pos = Camera.main.ViewportToWorldPoint(posInScreen);
		pos.x = _pos.x;
		pos.z = _pos.y;
		position = pos;
	}