Vector3.Reflect - wrong direction

[chelnok]

Hi,
trying to make bouncing laser. I found few examples using Vector3.Reflect, but cant get it work like i thought it would. I think there is something i cant understand or see anymore, or perhaps Reflect is not ment to be used like this:

function Update () 
{
	drawLaser(transform.position,3);
}

function drawLaser(startPoint:Vector3,n:int)  
{
	var hit : RaycastHit;
	var rayDir:Vector3 = transform.TransformDirection (Vector3.forward);
	 
	for(var i = 0; i < n; i++)
	{     
	    if (Physics.Raycast (startPoint, rayDir, hit, 1000)) 
	    {
		    Debug.DrawLine (startPoint, hit.point);
		 	rayDir = Vector3.Reflect(startPoint, hit.normal) ;
	    	startPoint = hit.point;
	    }
	}
}

And here is a picture (white line by code, green one from my mind):

[CodeMasterMike]

The Vector3.Reflect doesn’t give you a direction, but a position at the opposite of the orginal vector. So the function is more like a “Set position” for a mirror effect rather than making a laser bounce of a wall.

You have to make your own bounce calculation, which shouldn’t be too hard.

For instance:

If the laser bounces of something that is not a floor, then switch the x and/or z direction to the opposite. If the laser hits something that is a floor, change the y direction (if you would want to).

Good luck!

[chelnok]

Found my error after reading (again) other answers, and just staring the code… Here is the correct code:

function drawLaser(startPoint:Vector3,n:int)  
{
	var hit : RaycastHit;
	var rayDir:Vector3 = transform.TransformDirection (Vector3.forward);
	 
	for(var i = 0; i < n; i++)
	{     
	    if (Physics.Raycast (startPoint, rayDir, hit, 1000)) 
	    {
		    Debug.DrawLine (startPoint, hit.point);
	     rayDir = Vector3.Reflect( (hit.point - startPoint).normalized, hit.normal  ) ;
	    	    startPoint = hit.point;
	    }
	}
}

[test84]

Why did you normalize the result?

[chelnok]

well that was just a test, but i wanted to use the result later as direction vector, like:
transform.rigidbody.velocity = rayDir * speed;

Dunno how to use code in comment (code,pre doesnt work…) , so i put this as an answer.

Here is my bouncing lazer script:

var speed:int = 333;
private var prevPoint:Vector3;
private var rayDir:Vector3;

function Start () 
{
	prevPoint = transform.position;
	transform.rigidbody.velocity = transform.forward *speed;
}

function OnCollisionEnter (col : Collision)
{
	rayDir = Vector3.Reflect( (col.contacts[0].point - prevPoint).normalized, col.contacts[0].normal ) ;
	transform.rigidbody.velocity = rayDir * speed;
	prevPoint = col.contacts[0].point;
}