Get value -1 to 1 from direction between 2 points

Questions & Answers
1

So, this is somewhat of a loaded question and I will try to do my best to explain it.

I am creating a vehicle AI system, and the vehicle has a Steer(x) function. X ranges from -1(steer left) to 1(steer right).

I’m trying to find the value that I need to pass to that function to steer my vehicle accordingly to a target, in this case the next checkpoint.

An example: Imagine a vehicle to the right of a checkpoint, this function should return something like -0.2 to steer the vehicle back towards the checkpoint.

This is what i’ve tried:

         Vector3 relativePos = path.corners[0] - transform.position;
         Quaternion targetRotation = Quaternion.LookRotation(relativePos);

         float y = transform.eulerAngles.y;
         float DeltaAngle = Mathf.DeltaAngle(y, targetRotation.eulerAngles.y);

        Debug.Log(DeltaAngle / 360f);

and

float dot = Vector3.Dot(transform.forward.normalized, (_Target.position - transform.position).normalized);

However it doesn’t produce the correct steering value.

Any help would be appreciated.

2

It should be

float dot = Vector3.Dot(transform.right, (_Target.position - transform.position).normalized);

Keep in mind that the value would get smaller rather quick as closer you get to the right direction. So you would never actually reach the target direction. You could use a quadratic fall off. For this you would need to seperate the direction (sign) from the magnitude.

float dir = Mathf.Sign(dot);
float mag = Mathf.Abs(dot);
mag = Mathf.Pow(1f - mag, 2);
float steer = dir * (1f - mag);

Instead of 2 you could use a larger value to make the fall off more narrow around the target direction.