Allow opting out of water culling (#7318)

CHANGELOG.md

@@ -238,6 +238,7 @@
     Feature #7194: Ori to show texture paths
     Feature #7214: Searching in the in-game console
     Feature #7248: Searching in the console with regex and toggleable case-sensitivity
+    Feature #7318: Ability to disable water culling
     Feature #7468: Factions API for Lua
     Feature #7477: NegativeLight Magic Effect flag
     Feature #7499: OpenMW-CS: Generate record filters by drag & dropping cell content to the filters field

apps/openmw/mwrender/renderingmanager.cpp

@@ -1495,6 +1495,7 @@ namespace MWRender
         newChunkMgr.mTerrain->setTargetFrameRate(Settings::cells().mTargetFramerate);
         float distanceMult = std::cos(osg::DegreesToRadians(std::min(mFieldOfView, 140.f)) / 2.f);
         newChunkMgr.mTerrain->setViewDistance(mViewDistance * (distanceMult ? 1.f / distanceMult : 1.f));
+        newChunkMgr.mTerrain->enableHeightCullCallback(Settings::terrain().mWaterCulling);
 
         return mWorldspaceChunks.emplace(worldspace, std::move(newChunkMgr)).first->second;
     }

components/settings/categories/terrain.hpp

@@ -37,6 +37,7 @@ namespace Settings
             makeMaxStrictSanitizerFloat(0) };
         SettingValue<float> mObjectPagingMinSizeCostMultiplier{ mIndex, "Terrain",
             "object paging min size cost multiplier", makeMaxStrictSanitizerFloat(0) };
+        SettingValue<bool> mWaterCulling{ mIndex, "Terrain", "water culling" };
     };
 }
 

components/terrain/world.cpp

@@ -23,7 +23,6 @@ namespace Terrain
         , mParent(parent)
         , mResourceSystem(resourceSystem)
         , mBorderVisible(false)
-        , mHeightCullCallback(new HeightCullCallback)
         , mWorldspace(worldspace)
     {
         mTerrainRoot = new osg::Group;
@@ -67,7 +66,6 @@ namespace Terrain
         , mChunkManager(nullptr)
         , mCellBorder(nullptr)
         , mBorderVisible(false)
-        , mHeightCullCallback(nullptr)
         , mWorldspace(worldspace)
     {
         mTerrainRoot = new osg::Group;
@@ -143,6 +141,14 @@ namespace Terrain
             mChunkManager->clearCache();
     }
 
+    void World::enableHeightCullCallback(bool enable)
+    {
+        if (enable)
+            mHeightCullCallback = new HeightCullCallback;
+        else
+            mHeightCullCallback = nullptr;
+    }
+
     osg::Callback* World::getHeightCullCallback(float highz, unsigned int mask)
     {
         if (!mHeightCullCallback || mTerrainRoot->getNumChildren() == 0)

components/terrain/world.hpp

@@ -106,6 +106,7 @@ namespace Terrain
 
         Storage* getStorage() { return mStorage; }
 
+        void enableHeightCullCallback(bool enable);
         osg::Callback* getHeightCullCallback(float highz, unsigned int mask);
 
         void setActiveGrid(const osg::Vec4i& grid) { mActiveGrid = grid; }

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

@@ -205,3 +205,16 @@ object paging min size cost multiplier
 This setting adjusts the calculated cost of merging an object used in the mentioned functionality.
 The larger this value is, the less expensive objects can be before they are discarded.
 See the formula above to figure out the math.
+
+water culling
+-------------
+:Type:		boolean
+:Range:		True/False
+:Default:	True
+
+Controls whether water culling is used.
+
+Water culling is an optimisation that prevents the expensive rendering of water when it is
+evaluated to be below any visible terrain chunk, potentially improving performance in many scenes.
+
+You may want to opt out of it if it causes framerate instability or inappropriately invisible water on your setup.

files/settings-default.cfg

@@ -119,6 +119,9 @@ object paging min size merge factor = 0.3
 # Controls how inexpensive an object needs to be to utilize 'min size merge factor'.
 object paging min size cost multiplier = 25
 
+# Don't draw water if it's evaluated to be below all visible terrain
+water culling = true
+
 [Fog]
 
 # If true, use extended fog parameters for distant terrain not controlled by