Elevator Motion Going Up Smooth, Going Down Not Smooth

Questions & Answers
1

Hey all, I’m having trouble wracking my brain trying to figure out why my elevator going up is smooth but coming down it is very jerky in motion. Any help would be greatly appreciated. Thanks for your time.

using UnityEngine;
using System.Collections;

public class ElevatorController : MonoBehaviour {

	public float elevator_speed;
	public bool going_down = true;
	public bool going_up = false;
	public GameObject Elevator1;

	// Use this for initialization
	void Start () 
	{
		going_up = false;
		elevator_speed = 0;	
	}
		
	void OnCollisionStay2D(Collision2D coll)
	{

		var xfer = GetComponent<Transform>();

		if (coll.gameObject.tag == "hero")

		if (going_down == true)
		 
		{
			elevator_speed = 2;
			xfer.Translate(Vector3.down.normalized * elevator_speed * Time.deltaTime); //going down is herky jerky
		
		}

		else if (going_down == false && xfer.position.y < -0.57f)                  
		{
			//gameObject {Get Elevator1}
			//elevator = gameObject.tag == "elevator";
			elevator_speed = 2;
			xfer.Translate(Vector3.up * elevator_speed * Time.deltaTime); //going up is smooth
		}

		if (coll.gameObject.tag == "elevator_bottom") 
		{
			going_down = false; // does not work
			elevator_speed = 0; // does not work
		}
	}
}
2

I bet it’s because you’re doing this motion in OnCollisionStay2D. The elevator only moves when something is colliding with it. Going up, it continues to collide with whatever’s on top of it, so you get (mostly by accident) smooth motion. Going down, it departs from whatever’s on top of it, stops moving, waits for whatever that is to fall down and hit it, and then moves again.

You should move your elevator in the Update (or perhaps FixedUpdate) method instead. If you need it to respond in some way to things colliding with it, then use the collision events only to set the flags that make it move (e.g. going_up and going_down).