Character on moving platform with Interpolation

Questions & Answers
1

I am making my first game in Unity and I really enjoy it, but I have run into a very annoying problem. My game is a platform game where the character is always running right. My character has a rigidbody2D component attached to it. I am now trying to implement platforms moving up and down and I am using this script:

void Update()
{
		transform.position = Vector2.MoveTowards (transform.position, patrolPoints [pointToReach].position,moveSpeed * Time.deltaTime);

		if (transform.position == patrolPoints [pointToReach].position) 
		{
			if (pointToReach == patrolPoints.Length - 1) 
			{
				pointToReach = 0;
			}
			else
			{
				pointToReach++;
			}
		}
	}

I move the character by changing the velocity of the Rigidbody2D component. That is done with the code:

void FixedUpdate () 
	{
		if (alive && !levelWon) 
		{
			if (playerBody.velocity.x <= 0 && !onGround) 
			{ 
				playerBody.velocity = new Vector2 (playerBody.velocity.x, playerBody.velocity.y); 
			} 
			else
			{
				playerBody.velocity = new Vector2 (moveSpeed, playerBody.velocity.y); 
			}
		}
	}

It works beautifully but my problem is when my character lands on the moving platform, he is not moving smoothly with the platform because he is not attached to it. I came across a solution that I really like that involves making the character a child of the platform as long as it is on it so I used that:

void OnCollisionEnter2D(Collision2D target)
	{
		if (target.gameObject.tag == "MovingPlatform") 
		{
			transform.parent = target.gameObject.transform;
		}
	}

	void OnCollisionExit2D(Collision2D target)
	{
		if (target.gameObject.tag == "MovingPlatform") 
		{
			transform.parent = null;
		}	
	}

It works when I use the Interpolate setting None but the movement of my character is not smooth with this setting. I have been using interpolation with very smooth movement but it does not work with the moving platform. As soon as it lands on the platform and becomes a child of the platform it moves much more slowly than before, with extrapolation the problem is the opposite, he speeds up.

I hope I have made my problem clear, any thoughts or help is much appreciated

Thanks in advance - The confused game developer

2

Hey I had this exact same problem. Hopefully this won’t be my final solution but it seems to work in the mean time. In the script that parents the player to the moving platform I set the interpolation method to none when they connect and then set the interpolation method back to interpolate when they disconnect.

public class StickToPlatform : MonoBehaviour 
{
       Rigidbody2D BotBody;

	void Start ()
	{
		BotBody = GetComponent<Rigidbody2D> ();
	}

void OnTriggerEnter2D (Collider2D info)
	{
		if (info.tag == "Moving Platform") 
		{
			transform.parent = info.transform;
			BotBody.interpolation = RigidbodyInterpolation2D.None;
		}
	}
	void OnTriggerExit2D (Collider2D info)
	{
		if (info.tag == "Moving Platform" && transform.parent == info.transform) 
		{
			transform.parent = null;
			BotBody.interpolation = RigidbodyInterpolation2D.Interpolate;
		}
	}
}