done

TP3/Assets/Scripts/CarThings/Drift.cs

@@ -0,0 +1,50 @@
+using UnityEngine;
+
+public class Drift : MonoBehaviour
+{
+    [SerializeField] Rigidbody rb;
+    [SerializeField] private float baseLateralFrictionCoeff = 5f;
+    [SerializeField] private float lateralVelocityStartDriftThreshold = 10f;
+    [SerializeField] private float lateralVelocityTotalDriftThreshold = 15f;
+
+    [SerializeField] private TrailRenderer trailRendererLeft;
+    [SerializeField] private TrailRenderer trailRendererRight;
+
+
+    [SerializeField] RotateWithMouse moreRotateWhenDrift;
+
+    [SerializeField] [Range(1, 5)] float RotateLerpSpeedMultipler;
+
+    private float lateralFrictionCoeff;
+    private float baseRotateLerpSpeed;
+    private float newRotateLerpSpeed => baseRotateLerpSpeed * RotateLerpSpeedMultipler;
+    // Start is called once before the first execution of Update after the MonoBehaviour is created
+    void Start()
+    {
+        baseRotateLerpSpeed = moreRotateWhenDrift.lerpSpeed;
+    }
+
+    // Update is called once per frame
+    void FixedUpdate()
+    {
+        
+
+        Vector3 forwardVelocity = Vector3.Project(rb.linearVelocity, transform.forward);
+        Vector3 lateralVelocity = rb.linearVelocity - forwardVelocity;
+
+        // dynamicCoeff is equal to 1 when no drift is happening, and 0 when the drift is at its maximum
+        float dynamicCoeff = Mathf.InverseLerp(lateralVelocityTotalDriftThreshold, lateralVelocityStartDriftThreshold, lateralVelocity.magnitude);
+        trailRendererLeft.emitting = dynamicCoeff < 0.9f;
+        trailRendererRight.emitting = dynamicCoeff < 0.9f;
+
+
+        // When no drift -> lerpSpeed = baseRotateLerpSpeed, when drift -> lerpSpeed = newRotateLerpSpeed
+        moreRotateWhenDrift.lerpSpeed = Mathf.Lerp(newRotateLerpSpeed, baseRotateLerpSpeed, dynamicCoeff);
+        lateralFrictionCoeff = baseLateralFrictionCoeff * dynamicCoeff;
+        print(dynamicCoeff);
+
+        Vector3 lateralFrictionForce = -lateralVelocity * lateralFrictionCoeff;
+        rb.AddForce(lateralFrictionForce, ForceMode.Acceleration);
+    }
+
+}