Improve performance and tune ramp/planter collision behavior

include/rendering/terrain_manager.hpp

@@ -13,6 +13,7 @@
 #include <mutex>
 #include <atomic>
 #include <queue>
+#include <vector>
 #include <condition_variable>
 #include <glm/glm.hpp>
 
@@ -246,8 +247,8 @@ private:
 
     // Streaming parameters
     bool streamingEnabled = true;
-    int loadRadius = 2;      // Load tiles within this radius (5x5 grid for performance)
-    int unloadRadius = 3;    // Unload tiles beyond this radius
+    int loadRadius = 1;      // Load tiles within this radius (3x3 grid for better CPU/GPU perf)
+    int unloadRadius = 2;    // Unload tiles beyond this radius
     float updateInterval = 0.1f;  // Check streaming every 0.1 seconds
     float timeSinceLastUpdate = 0.0f;
 
@@ -257,8 +258,9 @@ private:
     static constexpr float TILE_SIZE = 533.33333f;          // One tile = 533.33 units
     static constexpr float CHUNK_SIZE = 33.33333f;          // One chunk = 33.33 units
 
-    // Background loading thread
-    std::thread workerThread;
+    // Background loading worker pool
+    std::vector<std::thread> workerThreads;
+    int workerCount = 0;
     std::mutex queueMutex;
     std::condition_variable queueCV;
     std::queue<TileCoord> loadQueue;