Creating a Physics Based Character Controller in Unity

Unity

The exercise here demonstrates implementing a customized physics controller in Unity.

For moving a 3D object, the required data is as followed.

• Direction
• Velocity
• Gravity

The direction input shall give left or right signal for movement. The velocity input shall accelerate the movement at a certain speed. The gravity input shall mimic real world physics.

So, create a C# script component on the player object and add the following code.

First of all, a proper handle to the character controller object is required and therefore use the Start method to get the handle.

private CharacterController _characterController;
void Start()
   {
       _characterController = GetComponent<CharacterController>();
   }

1. Direction

• In the Update method, create a private variable for holding the horizontal axis value.

float _horizontalInput = Input.GetAxis("Horizontal");

• Create a vector3 variable named direction to use the input received from the user.

Vector3 _direction = new Vector3(_horizontalInput, 0, 0);

2. Velocity

• Create a private speed variable with a value as per choice.

private int _speed = 5;

• In the Update method, create a vector3 variable for calculating the velocity.

Vector3 _velocity = _direction * _speed;

3. Gravity

• Create a private gravity variable with a value as per choice.

private int _gravity = 1;

• In the Update method, check for the bool value to see whether the player is grounded or in the air.
• If grounded, there can be another act done. If in the air, the velocity vector’s Y value shall be reduced.

if (_characterController.isGrounded == true)
       {
           
       }
       else
       {
           _velocity.y -= _gravity;
       }

Finally, use all the results to make the player move using the character controller.

_characterController.Move(_velocity * Time.deltaTime);

That should be it :)

Here is the final result.

PlayerMovementPhysicsController.mp4