MeshLOD: polish settings fields, bbox material, tracked car count

- Rename all MeshLodSettings public fields to camelCase (consistency
  with every other settings class in the project).
- Replace the proxy-box renderer's borrowed car material with a shared
  matte Standard material tinted to the car body albedo; cheaper at
  LOD3 distances and responds correctly to scene lighting at night.
- Expose GetTrackedCounts() and display loco/freight breakdown next to
  the Refresh Now button in the settings panel.

src/Modules/MeshLod/MeshLodInjector.cs

@@ -12,6 +12,7 @@ static class MeshLodInjector
 {
     static MeshLodSettings _settings = new();
     static readonly List<WeakReference<Car>> _trackedCars = new();
+    static Material? _bboxMat;
 
     // Debounced auto-refresh: set by MarkDirty, consumed by CheckAutoRefresh (called from Update).
     static float _pendingRefreshAt = -1f;
@@ -22,9 +23,9 @@ static class MeshLodInjector
     public static void Init(MeshLodSettings settings)
     {
         _settings = settings;
-        Log.Info($"MeshLOD settings: frac1={settings.Lod1RendererFraction:F2}  frac2={settings.Lod2RendererFraction:F2}  " +
+        Log.Info($"MeshLOD settings: frac1={settings.lod1RendererFraction:F2}  frac2={settings.lod2RendererFraction:F2}  " +
-                 $"d1={settings.Lod1Distance}m  d2={settings.Lod2Distance}m  d3={settings.Lod3Distance}m  " +
+                 $"d1={settings.lod1Distance}m  d2={settings.lod2Distance}m  d3={settings.lod3Distance}m  " +
-                 $"locos={settings.ApplyToLocomotives}  freight={settings.ApplyToFreightCars}  " +
+                 $"locos={settings.applyToLocomotives}  freight={settings.applyToFreightCars}  " +
                  $"lodBias={QualitySettings.lodBias:F2}");
     }
 
@@ -32,6 +33,19 @@ static class MeshLodInjector
     {
         _trackedCars.Clear();
         _pendingRefreshAt = -1f;
+        if (_bboxMat != null) { UnityEngine.Object.Destroy(_bboxMat); _bboxMat = null; }
+    }
+
+    public static (int total, int locos, int freight) GetTrackedCounts()
+    {
+        int total = 0, locos = 0;
+        foreach (var wr in _trackedCars)
+        {
+            if (!wr.TryGetTarget(out Car? car) || car == null) continue;
+            total++;
+            if (car is BaseLocomotive) locos++;
+        }
+        return (total, locos, total - locos);
     }
 
     // Called from the UI whenever any setting changes.
@@ -57,8 +71,8 @@ static class MeshLodInjector
         if (car.BodyTransform.GetComponent<LODGroup>() != null) return;
 
         bool isLoco = car is BaseLocomotive;
-        if ( isLoco && !_settings.ApplyToLocomotives) return;
+        if ( isLoco && !_settings.applyToLocomotives) return;
-        if (!isLoco && !_settings.ApplyToFreightCars)  return;
+        if (!isLoco && !_settings.applyToFreightCars)  return;
 
         MeshRenderer[] renderers = CollectRenderers(car.BodyTransform);
         if (renderers.Length == 0) return;
@@ -84,8 +98,8 @@ static class MeshLodInjector
             RemoveLods(car);
 
             bool isLoco = car is BaseLocomotive;
-            if ( isLoco && !_settings.ApplyToLocomotives) { skipped++; continue; }
+            if ( isLoco && !_settings.applyToLocomotives) { skipped++; continue; }
-            if (!isLoco && !_settings.ApplyToFreightCars)  { skipped++; continue; }
+            if (!isLoco && !_settings.applyToFreightCars)  { skipped++; continue; }
 
             MeshRenderer[] renderers = CollectRenderers(car.BodyTransform);
             if (renderers.Length == 0) { skipped++; continue; }
@@ -135,10 +149,10 @@ static class MeshLodInjector
             .OrderByDescending(r => BoundsVolume(r.bounds))
             .ToArray();
 
-        // LOD1: minor cull — keep the top Lod1RendererFraction of renderers
+        // LOD1: minor cull — keep the top lod1RendererFraction of renderers
-        int lod1Keep = Mathf.Max(1, Mathf.RoundToInt(sorted.Length * _settings.Lod1RendererFraction));
+        int lod1Keep = Mathf.Max(1, Mathf.RoundToInt(sorted.Length * _settings.lod1RendererFraction));
-        // LOD2: major cull — keep only the top Lod2RendererFraction (must be ≤ lod1Keep)
+        // LOD2: major cull — keep only the top lod2RendererFraction (must be ≤ lod1Keep)
-        int lod2Keep = Mathf.Clamp(Mathf.RoundToInt(sorted.Length * _settings.Lod2RendererFraction), 1, lod1Keep);
+        int lod2Keep = Mathf.Clamp(Mathf.RoundToInt(sorted.Length * _settings.lod2RendererFraction), 1, lod1Keep);
 
         Renderer[] lod0Rend = allRenderers.Cast<Renderer>().ToArray();
         Renderer[] lod1Rend = sorted.Take(lod1Keep).Cast<Renderer>().ToArray();
@@ -147,7 +161,7 @@ static class MeshLodInjector
         // LOD3: 12-triangle proxy box derived from the largest renderer's mesh-local AABB.
         Bounds localBounds = ComputeMeshLocalBounds(sorted[0], bodyRoot);
         MeshRenderer bboxMr = CreateBoundingBoxRenderer(bodyRoot, localBounds,
-                                                         sorted[0].sharedMaterial,
+                                                         GetOrCreateBBoxMat(sorted[0].sharedMaterial),
                                                          sorted[0].gameObject.layer);
         Renderer[] lod3Rend = new[] { (Renderer)bboxMr };
 
@@ -161,9 +175,9 @@ static class MeshLodInjector
         float lodBias      = Mathf.Max(QualitySettings.lodBias, 0.01f);
         float k            = sphereDiameter * lodBias / invFovFactor;
 
-        float lod1H = Mathf.Clamp(k / _settings.Lod1Distance, 0.001f, 0.999f);
+        float lod1H = Mathf.Clamp(k / _settings.lod1Distance, 0.001f, 0.999f);
-        float lod2H = Mathf.Clamp(k / _settings.Lod2Distance, 0.001f, lod1H * 0.9f);
+        float lod2H = Mathf.Clamp(k / _settings.lod2Distance, 0.001f, lod1H * 0.9f);
-        float lod3H = Mathf.Clamp(k / _settings.Lod3Distance, 0.001f, lod2H * 0.9f);
+        float lod3H = Mathf.Clamp(k / _settings.lod3Distance, 0.001f, lod2H * 0.9f);
 
         var lodGroup = bodyRoot.gameObject.AddComponent<LODGroup>();
         lodGroup.SetLODs(new LOD[]
@@ -253,6 +267,21 @@ static class MeshLodInjector
 
     // ── Proxy box mesh ────────────────────────────────────────────────────────
 
+    // One matte Standard material shared across all proxy boxes; tinted to the
+    // car body's albedo so it looks approximately correct under any lighting.
+    static Material GetOrCreateBBoxMat(Material? src)
+    {
+        if (_bboxMat != null) return _bboxMat;
+        var shader = Shader.Find("Standard") ?? Shader.Find("Legacy Shaders/Diffuse");
+        _bboxMat = shader != null ? new Material(shader) : new Material(src);
+        _bboxMat.color = src != null && src.HasProperty("_Color")
+            ? src.color
+            : new Color(0.45f, 0.45f, 0.45f);
+        if (_bboxMat.HasProperty("_Metallic"))   _bboxMat.SetFloat("_Metallic",   0f);
+        if (_bboxMat.HasProperty("_Glossiness")) _bboxMat.SetFloat("_Glossiness", 0.1f);
+        return _bboxMat;
+    }
+
     static MeshRenderer CreateBoundingBoxRenderer(Transform parent, Bounds localBounds,
                                                    Material mat, int layer)
     {

src/Modules/MeshLod/MeshLodSettings.cs

@@ -8,15 +8,15 @@ public class MeshLodSettings
     public bool enabled = false;
 
     // Fraction of renderers kept at each progressive cull level (sorted by bounds volume desc).
-    public float Lod1RendererFraction = 0.50f;  // minor cull: remove tiny details
+    public float lod1RendererFraction = 0.50f;  // minor cull: remove tiny details
-    public float Lod2RendererFraction = 0.15f;  // major cull: structural geometry only
+    public float lod2RendererFraction = 0.15f;  // major cull: structural geometry only
 
     // Distance in metres for each LOD transition.  Converted to Unity's
     // screenRelativeTransitionHeight at apply time, corrected for lodBias.
-    public float Lod1Distance = 80f;    // LOD0 → LOD1  (full detail → minor cull)
+    public float lod1Distance = 80f;    // LOD0 -> LOD1  (full detail -> minor cull)
-    public float Lod2Distance = 200f;   // LOD1 → LOD2  (minor cull → structural)
+    public float lod2Distance = 200f;   // LOD1 -> LOD2  (minor cull -> structural)
-    public float Lod3Distance = 600f;   // LOD2 → LOD3  (structural → proxy box)
+    public float lod3Distance = 600f;   // LOD2 -> LOD3  (structural -> proxy box)
 
-    public bool ApplyToLocomotives = true;
+    public bool applyToLocomotives = true;
-    public bool ApplyToFreightCars = true;
+    public bool applyToFreightCars = true;
 }

src/Modules/MeshLod/MeshLodSettingsUI.cs

@@ -23,11 +23,11 @@ static class MeshLodSettingsUI
         GUILayout.Label("<b>Apply to</b>");
         GUILayout.Space(4f);
 
-        bool newLocos = GUILayout.Toggle(s.ApplyToLocomotives, " Locomotives");
+        bool newLocos = GUILayout.Toggle(s.applyToLocomotives, " Locomotives");
-        if (newLocos != s.ApplyToLocomotives) { s.ApplyToLocomotives = newLocos; changed = true; }
+        if (newLocos != s.applyToLocomotives) { s.applyToLocomotives = newLocos; changed = true; }
 
-        bool newCars = GUILayout.Toggle(s.ApplyToFreightCars, " Freight / passenger cars");
+        bool newCars = GUILayout.Toggle(s.applyToFreightCars, " Freight / passenger cars");
-        if (newCars != s.ApplyToFreightCars) { s.ApplyToFreightCars = newCars; changed = true; }
+        if (newCars != s.applyToFreightCars) { s.applyToFreightCars = newCars; changed = true; }
 
         // ── Renderer fractions ────────────────────────────────────────────────
         GUILayout.Space(10f);
@@ -36,35 +36,35 @@ static class MeshLodSettingsUI
 
         int ex60 = 60;  // example car with 60 renderers
         GUILayout.Label(
-            $"  LOD1 (minor cull):   {s.Lod1RendererFraction * 100f:F0}% kept " +
+            $"  LOD1 (minor cull):   {s.lod1RendererFraction * 100f:F0}% kept " +
-            $"— {Mathf.Max(1, Mathf.RoundToInt(ex60 * s.Lod1RendererFraction))}/{ex60} for a 60-renderer car",
+            $"— {Mathf.Max(1, Mathf.RoundToInt(ex60 * s.lod1RendererFraction))}/{ex60} for a 60-renderer car",
             GUI.skin.label);
         GUILayout.BeginHorizontal();
         GUILayout.Space(4f);
-        float newF1 = GUILayout.HorizontalSlider(s.Lod1RendererFraction, 0.15f, 0.80f, GUILayout.Width(220f));
+        float newF1 = GUILayout.HorizontalSlider(s.lod1RendererFraction, 0.15f, 0.80f, GUILayout.Width(220f));
         GUILayout.EndHorizontal();
-        if (Mathf.Abs(newF1 - s.Lod1RendererFraction) > 0.005f)
+        if (Mathf.Abs(newF1 - s.lod1RendererFraction) > 0.005f)
         {
-            s.Lod1RendererFraction = Mathf.Round(newF1 * 20f) / 20f;  // snap to 5% steps
+            s.lod1RendererFraction = Mathf.Round(newF1 * 20f) / 20f;  // snap to 5% steps
-            if (s.Lod1RendererFraction <= s.Lod2RendererFraction)
+            if (s.lod1RendererFraction <= s.lod2RendererFraction)
-                s.Lod2RendererFraction = Mathf.Max(0.05f, s.Lod1RendererFraction - 0.10f);
+                s.lod2RendererFraction = Mathf.Max(0.05f, s.lod1RendererFraction - 0.10f);
             changed = true;
         }
 
         GUILayout.Space(4f);
         GUILayout.Label(
-            $"  LOD2 (structural):  {s.Lod2RendererFraction * 100f:F0}% kept " +
+            $"  LOD2 (structural):  {s.lod2RendererFraction * 100f:F0}% kept " +
-            $"— {Mathf.Max(1, Mathf.RoundToInt(ex60 * s.Lod2RendererFraction))}/{ex60} for a 60-renderer car",
+            $"— {Mathf.Max(1, Mathf.RoundToInt(ex60 * s.lod2RendererFraction))}/{ex60} for a 60-renderer car",
             GUI.skin.label);
         GUILayout.BeginHorizontal();
         GUILayout.Space(4f);
-        float newF2 = GUILayout.HorizontalSlider(s.Lod2RendererFraction, 0.05f, 0.40f, GUILayout.Width(220f));
+        float newF2 = GUILayout.HorizontalSlider(s.lod2RendererFraction, 0.05f, 0.40f, GUILayout.Width(220f));
         GUILayout.EndHorizontal();
-        if (Mathf.Abs(newF2 - s.Lod2RendererFraction) > 0.005f)
+        if (Mathf.Abs(newF2 - s.lod2RendererFraction) > 0.005f)
         {
-            s.Lod2RendererFraction = Mathf.Round(newF2 * 20f) / 20f;
+            s.lod2RendererFraction = Mathf.Round(newF2 * 20f) / 20f;
-            if (s.Lod2RendererFraction >= s.Lod1RendererFraction)
+            if (s.lod2RendererFraction >= s.lod1RendererFraction)
-                s.Lod1RendererFraction = Mathf.Min(0.80f, s.Lod2RendererFraction + 0.10f);
+                s.lod1RendererFraction = Mathf.Min(0.80f, s.lod2RendererFraction + 0.10f);
             changed = true;
         }
 
@@ -78,23 +78,29 @@ static class MeshLodSettingsUI
             GUI.skin.label);
         GUILayout.Space(4f);
 
-        DrawDistanceSlider(ref s.Lod1Distance, "LOD0→LOD1  (minor cull)", 30f, 500f, ref changed);
+        DrawDistanceSlider(ref s.lod1Distance, "LOD0→LOD1  (minor cull)", 30f, 500f, ref changed);
         GUILayout.Space(2f);
-        DrawDistanceSlider(ref s.Lod2Distance, "LOD1→LOD2  (structural)", s.Lod1Distance + 20f, 1000f, ref changed);
+        DrawDistanceSlider(ref s.lod2Distance, "LOD1→LOD2  (structural)", s.lod1Distance + 20f, 1000f, ref changed);
-        if (s.Lod2Distance <= s.Lod1Distance) { s.Lod2Distance = s.Lod1Distance + 50f; changed = true; }
+        if (s.lod2Distance <= s.lod1Distance) { s.lod2Distance = s.lod1Distance + 50f; changed = true; }
         GUILayout.Space(2f);
-        DrawDistanceSlider(ref s.Lod3Distance, "LOD2→LOD3  (proxy box) ", s.Lod2Distance + 20f, 1500f, ref changed);
+        DrawDistanceSlider(ref s.lod3Distance, "LOD2→LOD3  (proxy box) ", s.lod2Distance + 20f, 1500f, ref changed);
-        if (s.Lod3Distance <= s.Lod2Distance) { s.Lod3Distance = s.Lod2Distance + 100f; changed = true; }
+        if (s.lod3Distance <= s.lod2Distance) { s.lod3Distance = s.lod2Distance + 100f; changed = true; }
 
         // ── Manual refresh ────────────────────────────────────────────────────
         GUILayout.Space(10f);
         GUILayout.Label("  Settings auto-refresh loaded cars ~0.5 s after the last change.", GUI.skin.label);
         GUILayout.Space(4f);
+        GUILayout.BeginHorizontal();
         if (GUILayout.Button("Refresh Now", GUILayout.Width(120f)))
         {
             MeshLodModule.Persist();
             MeshLodInjector.RefreshAll();
         }
+        var (total, locos, freight) = MeshLodInjector.GetTrackedCounts();
+        GUILayout.Label(
+            $"  {total} tracked  ({locos} loco{(locos == 1 ? "" : "s")}, {freight} car{(freight == 1 ? "" : "s")})",
+            GUI.skin.label);
+        GUILayout.EndHorizontal();
 
         GUILayout.EndVertical();