Ackermann Steering Geometory for Unity in C#

AckermannSteering.cs

using UnityEngine;

public class AckermannSteering : MonoBehaviour
{
    [SerializeField] private float steeringAngle; // ステアリングの切れ角
    [SerializeField] private float tread; // 左右の車輪間の距離 (トレッド)
    [SerializeField] private float wheelBase; // 前後の車輪間の距離 (ホイールベース)

    public float leftWheelAngle { get; private set; } // 左車輪の角度
    public float rightWheelAngle { get; private set; } // 右車輪の角度
    public float turningRadius { get; private set; } // 回転半径
    public Vector3 turningCenter { get; private set; } // 回転中心

    void Update()
    {
        CalculateAckermannSteering(steeringAngle, tread, wheelBase);
    }

    private void CalculateAckermannSteering(float steeringAngle, float tread, float wheelBase)
    {
        float radianSteeringAngle = Mathf.Deg2Rad * steeringAngle;
        float tanSteeringAngle = Mathf.Tan(radianSteeringAngle);

        turningRadius = wheelBase / tanSteeringAngle; // 回転半径の計算

        // 回転中心の計算
        float turningCenterX = transform.position.x + (tread / 2) * Mathf.Cos(radianSteeringAngle);
        float turningCenterZ = transform.position.z - turningRadius * Mathf.Sin(radianSteeringAngle);
        turningCenter = new Vector3(turningCenterX, transform.position.y, turningCenterZ);

        // Ackermann steering geometryの計算
        float innerWheelAngle = Mathf.Rad2Deg * Mathf.Atan(wheelBase / (turningRadius + (tread / 2)));
        float outerWheelAngle = Mathf.Rad2Deg * Mathf.Atan(wheelBase / (turningRadius - (tread / 2)));

        // 左右の車輪の角度を設定
        if (steeringAngle > 0)
        {
            leftWheelAngle = outerWheelAngle;
            rightWheelAngle = innerWheelAngle;
        }
        else if (steeringAngle < 0)
        {
            leftWheelAngle = innerWheelAngle;
            rightWheelAngle = outerWheelAngle;
        }
        else
        {
            leftWheelAngle = 0;
            rightWheelAngle = 0;
            turningRadius = Mathf.Infinity;
            turningCenter = Vector3.zero;
        }
    }
}