Getting the angle between 2 objects

Hello there, I'm having some difficulty to get the angle between two objects and know if the target object is it at my right or my left...
If I use this, (the code down here) I can get an angle difference, but only in 180 degrees...

Code (csharp):

1.  
2.         var relativePos = nextPoint - transform.position;
3.         rotation = Quaternion.LookRotation(relativePos);
4.            
5.         var forward = transform.forward;
6.         var angle = Vector3.Angle(relativePos, forward);
7.  
8.         //angle and Quaternion.Angle(transform.rotation, rotation) brings me the same result. but still I can't see witch side the object are...

Hope anyone can help.
THANKS!

 

The trick is to check the cross product between the 2 vectors. In your case forward and relativePos (which isn't actually a position but a direction ). The cross product of two vectors are a new vector perpendicular to the plane defined by the vectors, so now you just need to check if the y component of the cross product is positive or negative (I.e. is the vector pointing up or down). Up = nextPoint is on the right, Down = to the left (See code snippet)

BTW: Obviously I don't know what your doing, but if the

Code (csharp):

1. rotation = Quaternion.LookRotation(relativePos)

line is actually

Code (csharp):

1. transform.rotation = Quaternion.LookRotation(relativePos)

I suggest that you move it after the rest of the code, otherwise the angle between the 2 object are always going to be 0 (since you've just rotate to face the other object directly).

Code (csharp):

1.  
2. var relativePos = nextPoint - transform.position;
3.          
4. var forward = transform.forward;
5. var angle = Vector3.Angle(relativePos, forward);
6. if (Vector3.Cross(forward, relativePos).y < 0) {
7.   //Do left stuff
8. }
9. else {
10.   //Do right stuff
11. }
12.  
13. rotation = Quaternion.LookRotation(relativePos);
14.  

 

I worked Talzor!!!
I Thank you very much!!!
I owe you one!

 

I prefer:
var something : Transform; // position of the other object

var p : Vector3 = transform.InverseTransformPoint(something.position);

Now p is the position of something in my local coordinate space. If p.y > 0, it's above me. If p.x < 0 it's to my left. If p.z < 0 it's behind me. Very convenient for writing any kind of AI code.

 

@Talzor : thanks a lot your code works like charm ....