From d182b9e6b05402a8114e1fdf2f568ec51448fe84 Mon Sep 17 00:00:00 2001
From: jimdroberts <jim.d.roberts@gmail.com>
Date: Thu, 1 Oct 2026 21:12:41 -0700
Subject: [PATCH] Use the 2D collision matrix for NetworkCollider2D when Layers
 is nothing

With Layers left at nothing, NetworkColliderBase derived the query mask from
Layers.GetInteractableLayersValue, which reads Physics.GetIgnoreLayerCollision,
the 3D matrix. NetworkTrigger2D and NetworkCollision2D query Physics2D, so they
used the wrong matrix and missed or added layers whenever the two matrices
differ. Add Layers.GetInteractableLayersValue2D, built from
Physics2D.GetIgnoreLayerCollision, and a protected virtual
GetInteractableLayersValue on NetworkColliderBase that NetworkCollider2D
overrides to use it.
---
 .../Component/Prediction/NetworkCollider2D.cs |  5 +++
 .../Prediction/NetworkColliderBase.cs         |  7 +++-
 .../GameKit/Dependencies/Utilities/Layers.cs  | 37 +++++++++++++++++++
 3 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/Assets/FishNet/Runtime/Generated/Component/Prediction/NetworkCollider2D.cs b/Assets/FishNet/Runtime/Generated/Component/Prediction/NetworkCollider2D.cs
index bad08e41..f7454fdd 100644
--- a/Assets/FishNet/Runtime/Generated/Component/Prediction/NetworkCollider2D.cs
+++ b/Assets/FishNet/Runtime/Generated/Component/Prediction/NetworkCollider2D.cs
@@ -59,6 +59,11 @@ protected override void OnDestroy()
             CollectionCaches<Collider2D>.StoreAndDefault(ref _hits, _hits.Length);
         }
 
+        /// <summary>
+        /// Returns the layers which interact with layer in the 2D collision matrix. Used when Layers is nothing.
+        /// </summary>
+        protected override int GetInteractableLayersValue(int layer) => GameKit.Dependencies.Utilities.Layers.GetInteractableLayersValue2D(layer);
+
         /// <summary>
         /// Called by the PredictionManager immediately before a reconcile begins.
         /// </summary>
diff --git a/Assets/FishNet/Runtime/Generated/Component/Prediction/NetworkColliderBase.cs b/Assets/FishNet/Runtime/Generated/Component/Prediction/NetworkColliderBase.cs
index 03d2745a..25deea20 100644
--- a/Assets/FishNet/Runtime/Generated/Component/Prediction/NetworkColliderBase.cs
+++ b/Assets/FishNet/Runtime/Generated/Component/Prediction/NetworkColliderBase.cs
@@ -147,13 +147,18 @@ protected bool TryPrepareColliderCheck(uint tick)
                 if (_lastGameObjectLayer != currentLayer)
                 {
                     _lastGameObjectLayer = currentLayer;
-                    InteractableLayers = GameKit.Dependencies.Utilities.Layers.GetInteractableLayersValue(currentLayer);
+                    InteractableLayers = GetInteractableLayersValue(currentLayer);
                 }
             }
 
             return true;
         }
 
+        /// <summary>
+        /// Returns the layers which interact with layer in the collision matrix. Used when Layers is nothing.
+        /// </summary>
+        protected virtual int GetInteractableLayersValue(int layer) => GameKit.Dependencies.Utilities.Layers.GetInteractableLayersValue(layer);
+
         /// <summary>
         /// Implement collider checking logic within this method.
         /// </summary>
diff --git a/Assets/FishNet/Runtime/Plugins/GameKit/Dependencies/Utilities/Layers.cs b/Assets/FishNet/Runtime/Plugins/GameKit/Dependencies/Utilities/Layers.cs
index edbecea3..fd5ef292 100644
--- a/Assets/FishNet/Runtime/Plugins/GameKit/Dependencies/Utilities/Layers.cs
+++ b/Assets/FishNet/Runtime/Plugins/GameKit/Dependencies/Utilities/Layers.cs
@@ -12,6 +12,10 @@ public static class Layers
         /// Lookup of interactable layers for each layer.
         /// </summary>
         private static Dictionary<int, int> _interactablesLayers;
+        /// <summary>
+        /// Lookup of interactable layers for each layer using the 2D collision matrix.
+        /// </summary>
+        private static Dictionary<int, int> _interactablesLayers2D;
 
         /// <summary>
         /// Tries to initializes InteractableLayers.
@@ -37,6 +41,30 @@ private static void TryInitializeInteractableLayers()
             }
         }
 
+        /// <summary>
+        /// Tries to initializes InteractableLayers2D.
+        /// </summary>
+        private static void TryInitializeInteractableLayers2D()
+        {
+            if (_interactablesLayers2D != null)
+                return;
+
+            _interactablesLayers2D = new();
+            for (int i = 0; i < 32; i++)
+            {
+                int mask = 0;
+                for (int j = 0; j < 32; j++)
+                {
+                    if (!Physics2D.GetIgnoreLayerCollision(i, j))
+                    {
+                        mask |= 1 << j;
+                    }
+                }
+                // Setting without add check is quicker.
+                _interactablesLayers2D[i] = mask;
+            }
+        }
+
         /// <summary>
         /// Returns interactable layers value for layer.
         /// </summary>
@@ -46,6 +74,15 @@ public static int GetInteractableLayersValue(int layer)
             return _interactablesLayers[layer];
         }
 
+        /// <summary>
+        /// Returns interactable layers value for layer using the 2D collision matrix.
+        /// </summary>
+        public static int GetInteractableLayersValue2D(int layer)
+        {
+            TryInitializeInteractableLayers2D();
+            return _interactablesLayers2D[layer];
+        }
+
         /// <summary>
         /// Returns interactable layers LayerMask for a GameObject.
         /// </summary>