diff --git a/src/DotRecast.Recast/RcLayerRegion.cs b/src/DotRecast.Recast/RcLayerRegion.cs
index 7c94007..dc98ecb 100644
--- a/src/DotRecast.Recast/RcLayerRegion.cs
+++ b/src/DotRecast.Recast/RcLayerRegion.cs
@@ -4,20 +4,20 @@ namespace DotRecast.Recast
 {
     public class RcLayerRegion
     {
-        public int id;
-        public int layerId; // Layer ID
-        public bool @base; // Flag indicating if the region is the base of merged regions.
+        public readonly int index;
+        public List<int> layers;
+        public List<int> neis;
         public int ymin, ymax;
-        public List<int> layers; // Layer count
-        public List<int> neis; // Neighbour count
+        public byte layerId; // Layer ID
+        public bool @base; // Flag indicating if the region is the base of merged regions.
 
         public RcLayerRegion(int i)
         {
-            id = i;
-            ymin = 0xFFFF;
-            layerId = 0xff;
+            index = i;
             layers = new List<int>();
             neis = new List<int>();
+            ymin = 0xFFFF;
+            layerId = 0xff;
         }
     };
 }
\ No newline at end of file
diff --git a/src/DotRecast.Recast/RcLayers.cs b/src/DotRecast.Recast/RcLayers.cs
index 98cee66..b9a2996 100644
--- a/src/DotRecast.Recast/RcLayers.cs
+++ b/src/DotRecast.Recast/RcLayers.cs
@@ -266,7 +266,7 @@ namespace DotRecast.Recast
             }
 
             // Create 2D layers from regions.
-            int layerId = 0;
+            byte layerId = 0;
 
             List<int> stack = new List<int>();
 
@@ -335,7 +335,7 @@ namespace DotRecast.Recast
                 if (!ri.@base)
                     continue;
 
-                int newId = ri.layerId;
+                byte newId = ri.layerId;
 
                 for (;;)
                 {
@@ -411,7 +411,7 @@ namespace DotRecast.Recast
             }
 
             // Compact layerIds
-            int[] remap = new int[256];
+            Span<byte> remap = stackalloc byte[256];
 
             // Find number of unique layers.
             layerId = 0;