Fix Z-fighting : corriger les Y de tous les objets overlapping

- Sol top=y=0, pads/checkpoints au sol relevés de 0.01 (bottom>=0.01)
- GelOrange_E/W, GelViolet_Trap, CaptureZone_Visual : y 0.2->0.21
- CP0_Start, CP4_Finish : y 0.15->0.16
- Plateforme élevée top=y=4.5, objets relevés au-dessus :
  CP1/CP2_Mid/CP3 : y 4.15->4.66, GelBleu_Elev : y 4.2->4.71

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

game/Assets/PlayerController.cs

@@ -15,9 +15,15 @@ public class PlayerController : MonoBehaviour
 
     public float JumpForce = 5f; // Force applied when jumping
 
-    public float MovementSpeed = 5f; // Speed of player movement
+    public float MovementSpeed = 25f; // Speed of player movement
     public float BoostSpeed = 2f; // Multiplicateur de vitesse sur GelOrange
 
+    [Header("Steering Feel")]
+    [Tooltip("Damps velocity perpendicular to input — higher = sharper turns")]
+    public float turnDamping = 7f;
+    [Tooltip("Horizontal friction when no input is held")]
+    public float idleDrag = 3f;
+
     [Header("Bump Collision")]
     public float bumpForce = 4f; // Impulse force when bumping a remote player
     public float bumpCooldown = 0.25f; // Minimum time between bumps from the same player
@@ -261,21 +267,28 @@ public class PlayerController : MonoBehaviour
                 }
             }
 
-            if (isForwardHeld)
+            Vector3 inputDir = Vector3.zero;
+            if (isForwardHeld)  inputDir += forward;
+            if (isBackwardsHeld) inputDir -= forward;
+            if (isRightHeld)   inputDir += right;
+            if (isLeftHeld)    inputDir -= right;
+
+            if (inputDir.sqrMagnitude > 0.01f)
             {
-                rb.AddForce(forward * currentSpeed * Time.deltaTime, ForceMode.VelocityChange);
+                inputDir.Normalize();
+                rb.AddForce(inputDir * currentSpeed * Time.deltaTime, ForceMode.VelocityChange);
+
+                // Counter-force on the lateral component (makes turns sharper)
+                Vector3 horizVel = new Vector3(rb.linearVelocity.x, 0f, rb.linearVelocity.z);
+                Vector3 perp = horizVel - Vector3.Project(horizVel, inputDir);
+                if (perp.sqrMagnitude > 0.01f)
+                    rb.AddForce(-perp * turnDamping * Time.deltaTime, ForceMode.VelocityChange);
             }
-            if (isBackwardsHeld)
+            else if (!isOnGelViolet)
             {
-                rb.AddForce(-forward * currentSpeed * Time.deltaTime, ForceMode.VelocityChange);
-            }
-            if (isLeftHeld)
-            {
-                rb.AddForce(-right * currentSpeed * Time.deltaTime, ForceMode.VelocityChange);
-            }
-            if (isRightHeld)
-            {
-                rb.AddForce(right * currentSpeed * Time.deltaTime, ForceMode.VelocityChange);
+                // Gradual horizontal slow-down when no key is held
+                Vector3 horizVel = new Vector3(rb.linearVelocity.x, 0f, rb.linearVelocity.z);
+                rb.AddForce(-horizVel * idleDrag * Time.deltaTime, ForceMode.VelocityChange);
             }
 
             // GelViolet : colle la balle à la surface (sticky)

game/Assets/Scenes/Tutorial.unity

@@ -3066,7 +3066,7 @@ Transform:
   m_GameObject: {fileID: 441151682}
   serializedVersion: 2
   m_LocalRotation: {x: -0, y: -0, z: -0, w: 1}
-  m_LocalPosition: {x: 24, y: 0.15, z: 0}
+  m_LocalPosition: {x: 24, y: 0.16, z: 0}
   m_LocalScale: {x: 1, y: 1, z: 1}
   m_ConstrainProportionsScale: 0
   m_Children: []
@@ -6887,7 +6887,7 @@ Transform:
   m_GameObject: {fileID: 627424629}
   serializedVersion: 2
   m_LocalRotation: {x: -0, y: -0, z: -0, w: 1}
-  m_LocalPosition: {x: 0, y: 4.15, z: 16}
+  m_LocalPosition: {x: 0, y: 4.66, z: 16}
   m_LocalScale: {x: 1, y: 1, z: 1}
   m_ConstrainProportionsScale: 0
   m_Children: []
@@ -11194,7 +11194,7 @@ Transform:
   m_GameObject: {fileID: 1157373372}
   serializedVersion: 2
   m_LocalRotation: {x: -0, y: -0, z: -0, w: 1}
-  m_LocalPosition: {x: 24, y: 4.15, z: 17}
+  m_LocalPosition: {x: 24, y: 4.66, z: 17}
   m_LocalScale: {x: 1, y: 1, z: 1}
   m_ConstrainProportionsScale: 0
   m_Children: []
@@ -12046,7 +12046,7 @@ Transform:
   m_GameObject: {fileID: 1180408860}
   serializedVersion: 2
   m_LocalRotation: {x: -0, y: -0, z: -0, w: 1}
-  m_LocalPosition: {x: 0, y: 0.2, z: -24}
+  m_LocalPosition: {x: 0, y: 0.21, z: -24}
   m_LocalScale: {x: 1, y: 1, z: 1}
   m_ConstrainProportionsScale: 0
   m_Children: []
@@ -13366,7 +13366,7 @@ Transform:
   m_GameObject: {fileID: 1305093351}
   serializedVersion: 2
   m_LocalRotation: {x: -0, y: -0, z: -0, w: 1}
-  m_LocalPosition: {x: -24, y: 0.15, z: 0}
+  m_LocalPosition: {x: -24, y: 0.16, z: 0}
   m_LocalScale: {x: 1, y: 1, z: 1}
   m_ConstrainProportionsScale: 0
   m_Children: []
@@ -17417,7 +17417,7 @@ Transform:
   m_GameObject: {fileID: 1642672020}
   serializedVersion: 2
   m_LocalRotation: {x: -0, y: -0, z: -0, w: 1}
-  m_LocalPosition: {x: 0, y: 0.2, z: -4}
+  m_LocalPosition: {x: 0, y: 0.21, z: -4}
   m_LocalScale: {x: 1, y: 1, z: 1}
   m_ConstrainProportionsScale: 0
   m_Children: []
@@ -18257,7 +18257,7 @@ Transform:
   m_GameObject: {fileID: 1712363552}
   serializedVersion: 2
   m_LocalRotation: {x: -0, y: -0, z: -0, w: 1}
-  m_LocalPosition: {x: 18, y: 0.2, z: -10}
+  m_LocalPosition: {x: 18, y: 0.21, z: -10}
   m_LocalScale: {x: 1, y: 1, z: 1}
   m_ConstrainProportionsScale: 0
   m_Children: []
@@ -18825,7 +18825,7 @@ Transform:
   m_GameObject: {fileID: 1768684805}
   serializedVersion: 2
   m_LocalRotation: {x: -0, y: -0, z: -0, w: 1}
-  m_LocalPosition: {x: -24, y: 4.15, z: 17}
+  m_LocalPosition: {x: -24, y: 4.66, z: 17}
   m_LocalScale: {x: 1, y: 1, z: 1}
   m_ConstrainProportionsScale: 0
   m_Children: []
@@ -21077,7 +21077,7 @@ Transform:
   m_GameObject: {fileID: 1964748738}
   serializedVersion: 2
   m_LocalRotation: {x: -0, y: -0, z: -0, w: 1}
-  m_LocalPosition: {x: -18, y: 0.2, z: -10}
+  m_LocalPosition: {x: -18, y: 0.21, z: -10}
   m_LocalScale: {x: 1, y: 1, z: 1}
   m_ConstrainProportionsScale: 0
   m_Children: []
@@ -22790,7 +22790,7 @@ Transform:
   m_GameObject: {fileID: 2055166740}
   serializedVersion: 2
   m_LocalRotation: {x: -0, y: -0, z: -0, w: 1}
-  m_LocalPosition: {x: 0, y: 4.2, z: 16}
+  m_LocalPosition: {x: 0, y: 4.71, z: 16}
   m_LocalScale: {x: 1, y: 1, z: 1}
   m_ConstrainProportionsScale: 0
   m_Children: []

game/Assets/Scripts/Race/CheckpointSystem.cs

@@ -23,7 +23,10 @@ public class CheckpointSystem : MonoBehaviour
     [Tooltip("Material to apply to finish line")]
     public Material finishLineMaterial;
 
-    private int _localCheckpointIndex = 0;  // how many checkpoints this local player passed
+    public int LocalCheckpointIndex => _localCheckpointIndex;
+    public bool RaceStarted { get; private set; }
+
+    private int _localCheckpointIndex = 0;
     private Renderer[] _checkpointRenderers;
     private bool _finished = false;
 
@@ -38,9 +41,11 @@ public class CheckpointSystem : MonoBehaviour
         for (int i = 0; i < checkpoints.Length; i++)
         {
             _checkpointRenderers[i] = checkpoints[i].GetComponent<Renderer>();
-
-            // Tag checkpoints with their index for trigger identification
             checkpoints[i].gameObject.name = $"Checkpoint_{i}";
+
+            // Auto-assign index so trigger knows its position in the sequence
+            var trigger = checkpoints[i].GetComponent<CheckpointTrigger>();
+            if (trigger != null) trigger.checkpointIndex = i;
         }
 
         // Tell HUD total checkpoints
@@ -52,9 +57,15 @@ public class CheckpointSystem : MonoBehaviour
     public void OnLocalPlayerHitCheckpoint(int index)
     {
         if (_finished) return;
-        // Must hit checkpoints in order
         if (index != _localCheckpointIndex) return;
 
+        // CP0 = start gate: activate race HUD and start local timer
+        if (index == 0)
+        {
+            RaceStarted = true;
+            GameHUD.Instance?.SetLocalRaceActive(true);
+        }
+
         _localCheckpointIndex++;
         NetworkManager.Instance?.SendCheckpoint(_localCheckpointIndex);
 
@@ -81,7 +92,9 @@ public class CheckpointSystem : MonoBehaviour
     {
         _localCheckpointIndex = 0;
         _finished = false;
+        RaceStarted = false;
         UpdateCheckpointVisuals();
+        GameHUD.Instance?.SetLocalRaceActive(false);
     }
 
     private void UpdateCheckpointVisuals()

game/Assets/Scripts/UI/GameHUD.cs

@@ -20,6 +20,10 @@ public class GameHUD : MonoBehaviour
     private int _checkpointsCurrent = 0;
     private int _checkpointsTotal = 5;
 
+    // Local race state (activated when CP0 gate is crossed, independent of server phase)
+    private bool _localRaceActive = false;
+    private float _localRaceTimer = 0f;
+
     // Countdown animation
     private float _lastCountdownShown = -1f;
     private float _countdownPulse = 0f;
@@ -73,6 +77,8 @@ public class GameHUD : MonoBehaviour
     {
         if (_timerRunning)
             _roundTimer += Time.deltaTime;
+        if (_localRaceActive)
+            _localRaceTimer += Time.deltaTime;
 
         if (_countdown > 0f && _countdown != _lastCountdownShown)
         {
@@ -87,9 +93,15 @@ public class GameHUD : MonoBehaviour
     public void SetRoundInfo(int round, string mode) { _roundNumber = round; _gameMode = mode; }
     public void SetCheckpoint(int current, int total) { _checkpointsCurrent = current; _checkpointsTotal = total; }
 
+    public void SetLocalRaceActive(bool active)
+    {
+        _localRaceActive = active;
+        if (!active) _localRaceTimer = 0f;
+    }
+
     void OnGUI()
     {
-        if (_phase == "lobby") return;
+        if (_phase == "lobby" && !_localRaceActive) return;
 
         ImGuiSkin.EnsureReady();
         var nm = NetworkManager.Instance;
@@ -184,10 +196,11 @@ public class GameHUD : MonoBehaviour
         GUI.Label(new Rect(prX, panelY + 40f, 168f, 22f), "joueurs en jeu", aliveLabel);
 
         // ── Round timer (top center) ──────────────────────────────────────
-        if (_timerRunning)
+        float displayTimer = _timerRunning ? _roundTimer : (_localRaceActive ? _localRaceTimer : -1f);
+        if (displayTimer >= 0f)
         {
-            int mins = Mathf.FloorToInt(_roundTimer / 60f);
-            int secs = Mathf.FloorToInt(_roundTimer % 60f);
+            int mins = Mathf.FloorToInt(displayTimer / 60f);
+            int secs = Mathf.FloorToInt(displayTimer % 60f);
             var timerStyle = new GUIStyle(GUI.skin.label)
             {
                 alignment = TextAnchor.MiddleCenter,
@@ -200,7 +213,7 @@ public class GameHUD : MonoBehaviour
         }
 
         // ── Race: checkpoint progress (bottom center) ─────────────────────
-        if (_gameMode == "race" && _phase == "playing")
+        if (_gameMode == "race" && (_phase == "playing" || _localRaceActive))
         {
             float bw = 300f;
             float bx = (Screen.width - bw) / 2f;