[Solved] Linear movement speed, reset position

Question

Hi all, visually here is what i'm trying to do:

From the ' X ' my Object starts and moves across to that wall. It collides with the wall that I've tagged 'SheetEnd'.
I want to have the object (the dark blue piece) reset its transform.position back to X, where it repeats motion #1.

**This form is glitchy on my computer...sorry for ugly layout of question...

I'll add the code...I feel i'm close...and am over-complicating this....any hints... or right directions would help.

    void Start()

 {
     initialPosition = transform.position;
 }

 // Update is called once per frame
 void Update()
 {
     //make a method that moves the MusicGuide from left to right
     if (state == State.Moving)
     {
         ScanLeftRight();
     } 
     if (state == State.FinishedMoving)
     {
         print("DING!");
         // Reset position and timer (if that's possible)
         // Change state back to Moving. 
     }
 }

 public void ScanLeftRight()
 {

     float timer = 0f;
     timer += Time.time;
     Vector3 musicGuidePosition = initialPosition + (vectorMagnitude * multiplier * (timer)); 
     transform.position = musicGuidePosition;

     // Ignore this code, was playing around with Sin() //
     //take an initial transform position and add an offset with respect to time. 
     //float cycle = Time.time / period;
     //float tau = 2 * Mathf.PI;
     //float oscillatingVector = Mathf.Sin(cycle * tau) / 2 + 0.5f;
     //print(oscillatingVector);
     //Vector3 musicGuidePosition = initialPosition - (vectorMagnitude * oscillatingVector);
     // update object's position so that it will move when game is running.
     //transform.position = musicGuidePosition;


 }

 private void ResetPosition()
 {
     if (state == State.FinishedMoving)

     {
         transform.position = new Vector3(8f, 10f, 4f);
         print("Reset Position " + transform.position);
                    
     }
 }

 void OnTriggerEnter(Collider other)
 {
     if (other.tag == "SheetEnd") // I have used the same tag that you attached to your enemy character
     {
         Debug.Log("Code made it this far... tagged ->");
         state = State.FinishedMoving;
         
         //reset position back to initial starting point once it reaches set distance
         ResetPosition();

     }
 }

}

[CODE]

alt text

Answer 1

@ OwnDemise,

You trying to do a LERP - a "LInear Interpolation" and there is nothing wrong with that, but it simpler to update the object position by the fraction of time each frame takes.

To do a LERP, you need to calculate the current location as a fraction of the total distance based on the ratio of current time taken to the total time you want to move that distance. it's a simple equation to solve for:

? / total distance to target from start = current time / total time to target. Solve each update for ? which represents the current location. So first you have to decide how long you want the move to take. Current time needs to be the Time.time - starting time.

For example, using LERP, if you want the total time to the target to be 6 seconds, and the current elapsed time is 3 seconds, no matter what the total distance from start to the target is, your object will be moved half that distance. If the current time is 4 seconds, the position of the object will be 4/6 or 2/3 of the that distance. You see the pattern? That's why it is a Linear interpolation!

The "easier" way is the most commonly used algorithm when it comes to motion - it does the same thing LERP does, but in a different way. It works without respect to the total distance or total time - it just keeps moving at a constant rate until you decide to stop (constant if your multiplier remains constant, that is)

      transform.position = transform.position + (vectorMagnitude * multiplier * Time.deltaTime ); 
      //
      Note: vectorMagnitude should give you the direction only.  
                       make sure that is normalized before you use it here
      those 3 values together determine how far to move in a given frame
      Take the simple example: you want to move 1 meter per second directly 
               to the right, the +x direction. 
      So the direction vector  normalized is  = (1,0,0)
      (Remove multiplier from the equation for now -  that is essentially a speed factor)
      //
      Time.deltaTime is the fraction of a second since the last frame.
      If our frame rate = 30fps, then Time.deltaTime = 1/30 = 0.0333 seconds
                 add that together 30 times and you have 1 second.
           //
      The calculation is:
            //
      object position = object position + direction vector * Time.deltaTime
   
      so:    + (1,0,0)  * time.Delta  therefore, in this simple example
                              we are adding 0.0333 of a meter to x every frame
       if you want to go faster, put your multiplier back in.

[Solved] Linear movement speed, reset position

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