Move using different speeds (front/back/lateral) while oriented independently of camera.

Hi, I'm trying to make a player move with different speeds (forward, backwards, lateral), while facing a target, independently of the actual camera angle. The inputs are based on a Xbox360 pad.

To do so, i have a _moveInputVector witch is then reoriented to be relative to the camera in world space, and used later as a velocity.
I calculate the difference between the desired movement direction (_moveInputVector) , and the actual character facing direction with Vector3.Dot() on both the forward and right axis.
It gives me a number between -1 and 1 that represents how much the desired direction axis matches the character facing direction axis.
Finally i use those numbers to calculate a final speed by adding the vertical speed and horizontal speed.

However, when i Debug.Log the Vector3.Dot results and add them, they go sightly beyond 1 sometimes (like 1.3f), which makes no sense for me since we can't be full forward speed (1.0f) AND a bit left/right (0.3f) at same time due to the use of a directional joystick.

Do anyone has an idea how to fix this ?

I'm aware there might be some better ways to achieve what i want but it's the only solution i found, so i'm also opened to different approaches.

Here is the code where speed is calculated :

Code (CSharp):

1. if(targetMode) // calculate speed when in target mode
2. {
3.     // the forward vector the player faces ( normalized before in the code )
4.     Vector3 targetDirForward = _lookInputVector;
5.     // the right of this facing direction
6.     Vector3 targetDirRight = new Vector3(targetDirForward.z, 0, -targetDirForward.x);
7.    
8.     // difference between the inputs direction and character facing direction    
9.     float dotForward = Vector3.Dot(targetDirForward, _moveInputVector);
10.     // same but with the right vector
11.     float dotRight = Vector3.Dot(targetDirRight, _moveInputVector);
12.  
13.     // if we move forward according to facing direction, add forward speed proportional to the "amount of forward" we are trying to move
14.     if (dotForward > 0) finalSpeed += Mathf.Abs(dotForward) * currSpeedSet.fwdMaxSpeed;
15.     // same for if move backwards
16.     else finalSpeed += Mathf.Abs(dotForward) * currSpeedSet.backMaxSpeed;
17.  
18.     // add the lateral speed (always proportional to how much we try to move on the left/right of the player facing direction)
19.     finalSpeed += Mathf.Abs(dotRight) * currSpeedSet.lateralMaxSpeed;
20. }
21.                  
22. // make the velocity proportionnal to finalSpeed and apply velocity
23. targetMovementVelocity = reorientedInput * finalSpeed;
24. currentVelocity = targetMovementVelocity;

 

Nevermind i found a solution for this. If anyone has the same problem, it came from the fact the joystick inputs were squared (so 45° on the pad would not mean 0.5 + 0.5 but a little more).

With this function it fixes it so when i'm full Top Down Left or Right, value will be 1 but if i go 45°, those 1 will be shared between the 2 axis (like 0.7 top 0.3 right).

Code (CSharp):

1. public static Vector3 ClampDiamond(Vector3 vector, float maxLength) // Diamond inputs instead of squared (for pad)
2.     {
3.         float diamondSize = Mathf.Abs(vector.x) + Mathf.Abs(vector.z);
4.         if (diamondSize > maxLength)
5.         {
6.             return vector / diamondSize * maxLength;
7.         }
8.         else
9.         {
10.             return vector;
11.         }
12.     }

I made it in a Vector3 but can be made as Vector2 aswell.