player.cs

using Godot;

public partial class Player : CharacterBody3D
{
    // Don't forget to rebuild the project so the editor knows about the new export variable.

    // How fast the player moves in meters per second.
    [Export]
    public int Speed { get; set; } = 14;
    // The downward acceleration when in the air, in meters per second squared.
    [Export]
    public int FallAcceleration { get; set; } = 75;

    private Vector3 _targetVelocity = Vector3.Zero;

    public override void _PhysicsProcess(double delta)
    {
        var direction = Vector3.Zero;

        if(Input.IsActionPressed("move_right"))
        {
            direction.X += 1f;
        }
        if(Input.IsActionPressed("move_left"))
        {
            direction.X -= 1f;
        }
        if(Input.IsActionPressed("move_back"))
        {
            direction.Z += 1f;
        }
        if(Input.IsActionPressed("move_forward"))
        {
            direction.Z -= 1f;
        }

        if (direction != Vector3.Zero)
        {
            direction = direction.Normalized();
            // Setting the basis property will affect the rotation of the node.
            GetNode<Node3D>("Pivot").Basis = Basis.LookingAt(direction);
        }

        // Ground velocity
        _targetVelocity.X = direction.X * Speed;
        _targetVelocity.Z = direction.Z * Speed;

        // Vertical velocity
        if (!IsOnFloor()) // If in the air, fall towards the floor. Literally gravity
        {
            _targetVelocity.Y -= FallAcceleration * (float)delta;
        }

        // Moving the character
        Velocity = _targetVelocity;
        MoveAndSlide();
    }
}