Add setting to allow following creatures to find path over water surface

apps/launcher/advancedpage.cpp

@@ -108,6 +108,7 @@ bool Launcher::AdvancedPage::loadSettings()
         int numPhysicsThreads = mEngineSettings.getInt("async num threads", "Physics");
         if (numPhysicsThreads >= 0)
             physicsThreadsSpinBox->setValue(numPhysicsThreads);
+        loadSettingBool(allowNPCToFollowOverWaterSurfaceCheckBox, "allow actors to follow over water surface", "Game");
     }
 
     // Visuals

apps/openmw/mwmechanics/aipackage.cpp

@@ -411,10 +411,15 @@ bool MWMechanics::AiPackage::isReachableRotatingOnTheRun(const MWWorld::Ptr& act
 
 DetourNavigator::Flags MWMechanics::AiPackage::getNavigatorFlags(const MWWorld::Ptr& actor) const
 {
+    static const bool allowToFollowOverWaterSurface = Settings::Manager::getBool("allow actors to follow over water surface", "Game");
+
     const MWWorld::Class& actorClass = actor.getClass();
     DetourNavigator::Flags result = DetourNavigator::Flag_none;
 
-    if (actorClass.isPureWaterCreature(actor) || (getTypeId() != AiPackageTypeId::Wander && actorClass.canSwim(actor)))
+    if (actorClass.isPureWaterCreature(actor)
+        || (getTypeId() != AiPackageTypeId::Wander
+            && ((allowToFollowOverWaterSurface && getTypeId() == AiPackageTypeId::Follow)
+                || actorClass.canSwim(actor))))
         result |= DetourNavigator::Flag_swim;
 
     if (actorClass.canWalk(actor))

docs/source/reference/modding/settings/game.rst

@@ -439,3 +439,19 @@ graphic herbalism
 Some mods add harvestable container models. When this setting is enabled, activating a container using a harvestable model will visually harvest from it instead of opening the menu.
 
 When this setting is turned off or when activating a regular container, the menu will open as usual.
+
+allow actors to follow over water surface
+---------------------
+
+:Type:		boolean
+:Range:		True/False
+:Default:	True
+
+If enabled actors will always find path over the water surface when following other actors. This makes OpenMW behaviour closer to the vanilla engine.
+
+If disabled actors without the ability to swim will not follow other actors to the water.
+
+.. note::
+    Has effect only when Navigator is enabled.
+
+This setting can be controlled in Advanced tab of the launcher.

files/settings-default.cfg

@@ -364,6 +364,10 @@ always allow stealing from knocked out actors = false
 # Enables visually harvesting plants for models that support it.
 graphic herbalism = true
 
+# Give actors an ability to swim over water surface when they follow other actor independently from their ability to swim
+# (true, false)
+allow actors to follow over water surface = true
+
 [General]
 
 # Anisotropy reduces distortion in textures at low angles (e.g. 0 to 16).

files/ui/advancedpage.ui

@@ -153,6 +153,16 @@
            </property>
           </widget>
          </item>
+         <item row="6" column="1">
+          <widget class="QCheckBox" name="allowNPCToFollowOverWaterSurfaceCheckBox">
+           <property name="toolTip">
+            <string>Give NPC an ability to swim over the water surface when they follow other actor independently from their ability to swim. Has effect only when nav mesh building is enabled.</string>
+           </property>
+           <property name="text">
+            <string>Always allow NPC to follow over water surface</string>
+           </property>
+          </widget>
+         </item>
         </layout>
        </item>
        <item>