RayCasting : debug.drawline / DrawRay + hit.normal not working

Unity Engine
1

Hi,

I am following this page :

I am looking at getting the normal of the face my ray is touching (projecting down from my player, will then align the said player to that normal…)

here’s my code :

    void Update()
    {
  
        RaycastHit hit;
        float distanceToGround = 0;
        if (Physics.Raycast(transform.position, Vector3.down, out hit))
        distanceToGround = hit.distance;
        Vector3 incomingVec = hit.point - transform.position;
        Vector3 reflectVec = Vector3.Reflect(incomingVec, hit.normal);

        Debug.DrawLine(transform.position, hit.point, Color.red);
        Debug.DrawRay(hit.point, reflectVec, Color.green);
        print(incomingVec);
        print("incomingVec");
        print(hit.normal);
        print("hit.normal");
}

The two debugs don’t display any line whatsoever

and

the results I get from my prints seems totally wrong :
hit.normal = (0.0, 1.0, 0.0) <= will keep being 0 1 0 no matter the surface inclination …

incomingVec = (0.0, -10.2, 0.0)

I was thinking I am maybe sending my ray in the wrong direction so its actually not hitting anything ? Dificult to say , in that case I would expect only 0 0 0 in the hit normal …

Help much appreciated,

thanks !

2

You’re missing some brackets. That’s for sure. Don’t know if there are other problems.

void Update(){
       RaycastHit hit;
       float distanceToGround = 0;
        if (Physics.Raycast(transform.position, Vector3.down, out hit)){
        distanceToGround = hit.distance;
        Vector3 incomingVec = hit.point - transform.position;
        Vector3 reflectVec = Vector3.Reflect(incomingVec, hit.normal);

        Debug.DrawLine(transform.position, hit.point, Color.red);
        Debug.DrawRay(hit.point, reflectVec, Color.green);
        print(incomingVec);
        print("incomingVec");
        print(hit.normal);
        print("hit.normal");
    }


}
3

thanks, indeed (weird I didnt get any error…) … but unfortunately the results stays the exact same :confused:

4

Instead of asking “Am I hitting nothing” you might want to ask “Am I hitting myself?” or even “What am I hitting?”

Try checking the ray cast hit.transform in your debug section.

Good luck!

1 Like
5

Thanks ! indeed looking at the hit.transforms helped me a lot !
I can now align my character to the normal of the hit by calculating the angle between the two vectors (with nice and kind euler.rotations, the quaternion lookat just go crazy…)… a bit rough still (still some work to do for the case the character is not facing the slop, smoothing up the thing)… but I am getting there.

thanks !

6

The reason for that is the alternative notation of the IF Statement

if(condition){
//code
//code
//code
}

and

if(condition)
//code

Without any brackets the IF statement applies to the next line. And ONLY to the next line.