void vSlerp(btQuaternion& start, btQuaternion& end, float t)
{
	 
	start = start.normalize();
	end = end.normalize();

	float dot = start.dot(end); //Finds the dot product
  
  	//We need the absolute value of dot
	if (dot < 0){
		dot = dot *-1; //don't know if your start.dot does this.
	}
  
	if (dot > 0.999995)
	{
	//Interpolate, this is where everything gets done
     	btQuaternion& Result = start + t*(end – start);//This is just liniar interpolation
      
      	dot = Result.normalize();
	}
  	
	//Now if dot is negative it means it's taking the long path, we want it to take the shorter path
	//To do this we reverse one of the Quaternion so that the rotation goes to the other side
	else if (dot < 0)
	{
	end = end *-1;//Now it thinks the end is on the other side
	dot = dot *-1;
	}
  
	//We want some kind of safty here because of floating point errors.
  	dot = clamp(dot,-1,1);
  
  	float StartToEndAngle = acos(dot);
  	float StartToResultAngle = StartToEndAngle * t;
  	
  	Quaternion basis = end – start*dot;
  	basis.normalize();
  
  	//Now we should get a smooth animation with it always taking the shortest path
  	return start*cos(StartToResultAngle) + basis*sin(StartToResultAngle);
}