Question Calculate movement vector relative to aim in order to make strafe animations

SOLVED - my answer is below

Hi,
I am making 3D top down shooter in Unity and I am facing a problem. Camera is fixed and is not rotating, so when you press left button it will rotate the player and move forwards to left. It is working well, but problem is when player is aiming. In my game player has ability to aim while holding right mouse button. I want to make strafe animations while aiming. I have created this blend tree in animator:



I have two parameters there: AimingWalkHorizontal and AimingWalkVertical. When the values are [1,0] it will play strafe right animation.

I have two Vectors. One for movement and one for aiming:

Code (CSharp):

1. Vector3 movementVector = new Vector3(_movementVector.x, 0, _movementVector.y);
2. Vector3 aimingDirection = new Vector3((MouseWorldPosition - PlayerController.PlayerObj.transform.position).x, 0, (MouseWorldPosition - PlayerController.PlayerObj.transform.position).z);

And I want to achieve this:



How can I get this relative movement Vector in order to feed it to animator?

Code (CSharp):

1. PlayerController.Animator.SetFloat("AimingWalkHorizontal", /* ??? */);
2. PlayerController.Animator.SetFloat("AimingWalkVertical", /* ??? */);

Thank you

 

Are you rotating a transform to point towards the player is aiming? Then just use

transform.right

to get a perpendicular direction (assuming the player is facing towards the transform forward direction), which you can fed into your animator.

Otherwise if you are generating a direction the player is facing in, you can use

Vector.Cross

to generate a perpendicular one.

 

If your aiming would be the same as your character's rotation, you can use Transform.InverseTransformDirection(Vector3), which transforms a direction from world space to your character's local space. Then you can take the x,z value out and put in the animator.

 

Problem is that I cannot just use perpendicular Vector using transform.right, because it was just example. Player can also aim same direction or diagonal and so on...

 

I have finally solved it by calculating clockwise angle between movement and aim vector. Than I am converting angle to normalized vector that is pushed to animator.

Code (CSharp):

1. Vector3 movementVector = new Vector3(_movementVector.x, 0, _movementVector.y).normalized;
2. Vector3 aimingDirection = new Vector3((MouseWorldPosition - PlayerController.PlayerObj.transform.position).x, 0, (MouseWorldPosition - PlayerController.PlayerObj.transform.position).z).normalized;
3.  
4. // Calculate clockwise angle between movement and aiming direction
5. float dotProduct = Vector3.Dot(movementVector, aimingDirection);
6. float crossProductMagnitude = Vector3.Cross(movementVector, aimingDirection).y;
7. float clockwiseAngle = Mathf.Atan2(crossProductMagnitude, dotProduct) * Mathf.Rad2Deg;
8.  
9. // In my game I have ability to rotate camera with middle mouse button, so I have to decrease angle by camera rotation
10. // If you have fixed camera rotation do not use this line
11. clockwiseAngle -= CameraController.Instance.CameraObj.transform.eulerAngles.y;
12.  
13. // Adjust the angle to be positive (0 to 360 degrees)
14. clockwiseAngle = (clockwiseAngle + 360) % 360;
15.  
16. // Convert angle to normalized vector
17.  
18. // Convert to radians
19. float radians = clockwiseAngle * Mathf.Deg2Rad;
20.  
21. // Calculate vector axis
22. float x = Mathf.Cos(radians);
23. float z = Mathf.Sin(radians);
24.  
25. // Create normalized vector
26. Vector3 relativeMovement = new Vector3(x, 0f, z).normalized;
27.  
28. // Set values to animator
29. PlayerController.Animator.SetFloat("AimingWalkHorizontal", relativeMovement.z * -1f);
30. PlayerController.Animator.SetFloat("AimingWalkVertical", relativeMovement.x);