Unity3d Quaternion LookRotation not returning proper value

Question

I wanted a projectile to look at the target object, to do that I am using Quaternion LookRotation as below

targetRotation = Quaternion.LookRotation(targetPosition - projectile.transform.position);
if(targetRotation.eulerAngles.magnitude <= 60)
  projectile.transform.rotation = targetRotation;

here I have put if condition to make it more realistic turn towards target, otherwise projectile should not turn if its more 60 degree turn.

now as in below image, we can see that the target object in not more than at 60 degree angle, but still while debugging I am getting 328 as targetRotation.eulerAngles.magnitude, which is getting the if condition failed and projectile is not rotating towards the target object.

Answer 1

Quaternion.LookRotation(targetPosition - projectile.transform.position) means "Give me a quaternion that represents a rotation of a vector from up towards targetPosition - projectile.transform.position". eulerAngles is just another representation of the rotation and you won't get anything meaningful from its magnitude.

I suspect you don't want that. Instead, I suspect you want to know whether or not the projectile would need to turn more than 60 degrees from its current forward direction. In that case, you probably want to check the angle between the projectile's forward vector and its direction vector towards the target.

I don't have Unity open so I don't know if this compiles, but it should go something like this:

var directionToTarget = targetPosition - projectile.transform.position;
var angleToTarget = Vector3.Angle(projectile.transform.forward, directionToTarget);
if (angleToTarget < 60) ...

You mentioned you want a more "realistic" turn. What do you want the projectile to do if it's more than 60 degrees?