Track platforms so you can ride them around reliably.

PlatformMotionRecorder.cs

//
// @kurtdekker
//
// Purpose: to be able to track arbitrary moving surfaces
// you want to hop on and ride around (platforms, etc.)
//
// Requires you to know if you are grounded or not.
//
// To use:
//
// Put this on any non-rotating moving platform object
// and it will track its instantaneous velocity.
// Put one of these on EVERY moving platorm.
//
// Over on your player controller:
//
// When your agent is grounded, raycast down from your agent
// and GetComponent<PlatformMotionRecorder>() on the collider you hit.
//
// In your LateUpdate(), if there was a PlatformMotionRecorder found
// above, get its .Movement property and add it to your own
// movement amount this frame.
//
// That's it. You're done.
//
// Can be used with 2D or 3D, doesn't matter.
//
// Future stretch goal:
//
//	- track target rotation in the same way
//	- make a GetMovement() method that accepts a "touch point"
//		from the playe. Use the last rotation to project curving
//		motion out appropriate to that point on the moving platform 
//		(eg, the far corner versus the rotational center of it).
//

using UnityEngine;

public class PlatformMotionRecorder : MonoBehaviour
{
	public Vector3 Movement { get; private set; }

	Vector3 lastPosition;

	void Update ()
	{
		Vector3 position = transform.position;

		Movement = position - lastPosition;

		lastPosition = position;
	}
}