How can I Vector3 Slerp or Lerp locally?

Questions & Answers
1

Hello, I’m using:

if(forwardMoveSpeed > 0){
	this.transform.localPosition = Vector3.Lerp(this.transform.position , new Vector3(this.transform.position.x  + 1f,this.transform.position.y, this.transform.position.z), forwardMoveSpeed * Time.deltaTime);
    forwardMoveSpeed -= 0.05f;
}

to move my character for a small amount of time. But this moves it in the global x position. As soon as my character rotates it doesn’t look right, obviously.

How can I move my character in it’s local x position.

Thanks.

I did some searches and found a bunch on how to rotate something locally/globally but nothing about just moving using Vector3.

EDIT:

So let me explain a tad bit more so you can get a better understanding.

I have a character(GameObject). He runs a path and has a specific amount of life. When he dies I want him to fall “forward” while doing his dying animation.

He faces the Z axis, therefore “forward” is his LOCAL Z axis. The path he travels has 90 degree turns. So he faces different directions relative to the global axis. Sometimes his LOCAL z axis is facing the GLOBAL x axis, sometimes the GLOBAL y Axis.

With that being said all I want to do is move his overall position’s LOCAL z axis by like 2 units while he’s doing his animation. (so if his position is 0,0,0 then when he dies I want his LOCAL position to be 0,0,2. I can’t just change his position because his LOCAL Z axis might be the GLOBALS X axis).

How do I do that?

Eveything I try moves him 2 units in a GLOBAL axis.

2

if you want to move the character in local-space, shouldn’t you be using Lerp on the transform.localposition and not transform.position? Try this instead

if(forwardMoveSpeed > 0){
    this.transform.localPosition = Vector3.Lerp(this.transform.localposition , new Vector3(this.transform.localposition.x  + 1f,this.transform.localposition.y, this.transform.localposition.z), forwardMoveSpeed * Time.deltaTime);
    forwardMoveSpeed -= 0.05f;
}
3

I’m not sure exactly what you to happen here. Typically you would have something like this:

var v3LocalDest : Vector3;
var speed = 2.0;

function Start() {
  v3LocalDest = transform.localPosition;
  v3LocalDest.x += 1.0;
}

function Update() {
    transform.localPosition = Vector3.Lerp(transform.localPosition, v3LocalDest, Time.deltaTime * speed);
}

Note if you have a global position and want to set v3LocalDest, you can do:

var v3LocalDest = transform.InverseTransformPoint(v3GlobalPoint);
4

Ok so I couldn’t find a solution so I just made my own personal converter. This code is pretty specific to my model but if your “forward” is your local Z axis then it might work for you.

Thanks to everyone who tried to help, maybe I didn’t explain it good enough.

            if(forwardMoveSpeed > 0){
				/*@@@@LEGEND
				 *In a perfect world, if all rotations were EXACT then this is what way the character is facing 
				 * 
				 * 
				 * If it's y rotation is 90 degrees: He is facing X direction and forward is +x
				 * 
				 * If it's y rotation is 0 degrees: He is facing Z direction and forward is +Z
				 * 
				 * If it's y rotation is 180 degrees: He is facing Z direction and forward is -z
				 * 
				 * If it's y rotation is 270 degrees: He is facing X direciont and forward is -x
				 * 
				 */
				
				
				currentPosition = this.transform.position;			
				float moveAmount = 2f;
				
	
				if(oneShot){
					float currentRotitation = this.transform.rotation.eulerAngles.y;
					//ALL VALUES ARE A RANGE/ABOUT BECAUSE WE CAN'T GAURENTEE THE CHARACTER'S ROTATION WILL BE EXACTLY 0,90,180, OR 270
					//if rotoation is greater then 20 then it CANT be "0" rotation
					if(currentRotitation > 20){
						//if rotation is greater then 110 then it CANT be "90" rotation
						if(currentRotitation > 110){
							//if rotation is greater then 200 then it CANT be "180" rotation
							if(currentRotitation > 200){
								//if we are greater then 200 we have to be at "270" degrees
								//forward is negative x
								nextPosition = new Vector3(currentPosition.x - moveAmount, currentPosition.y, currentPosition.z);	
							}
							//if it's less then 200 then it has to be "180" degrees
							else{
								//forward is negative z
								nextPosition = new Vector3(currentPosition.x, currentPosition.y, currentPosition.z - moveAmount);	
							}
						}
						//if it's less then 110 it has to be "90" rotation
						else{
							//forward is positive x
							nextPosition = new Vector3(currentPosition.x + moveAmount, currentPosition.y, currentPosition.z);
						}
						
						
					}
					//if it's less then 20 it must be "0" rotation
					else{
						//forward is positive Z
						nextPosition = new Vector3(currentPosition.x, currentPosition.y, currentPosition.z + moveAmount);
					}
					//this is so we only figure out our "end" location once.
					oneShot = false;	
				}
					
			
				
				this.transform.position = Vector3.Slerp(currentPosition , nextPosition, forwardMoveSpeed * Time.deltaTime);
				forwardMoveSpeed -= 0.05f;
			}