When a custom near clip plane is used, we need to fix up a second viewproj matrix manually to get proper depth values in the vertex shader. This fixes fog on reflections.

apps/openmw/mwrender/refraction.cpp

@@ -8,6 +8,8 @@
 #include <OgreViewport.h>
 #include <OgreRoot.h>
 
+#include <extern/shiny/Main/Factory.hpp>
+
 #include "renderconst.hpp"
 
 namespace MWRender
@@ -30,7 +32,7 @@ namespace MWRender
         vp->setOverlaysEnabled(false);
         vp->setShadowsEnabled(false);
         vp->setVisibilityMask(RV_Actors + RV_Misc + RV_Statics + RV_StaticsSmall + RV_Terrain + RV_Sky);
-        vp->setMaterialScheme("water_reflection");
+        vp->setMaterialScheme("water_refraction");
         vp->setBackgroundColour (Ogre::ColourValue(0.0078, 0.0576, 0.150));
         mRenderTarget->setAutoUpdated(true);
         mRenderTarget->addListener(this);
@@ -54,6 +56,12 @@ namespace MWRender
         mCamera->setAspectRatio(mParentCamera->getAspectRatio());
         mCamera->setFOVy(mParentCamera->getFOVy());
 
+        // for depth calculation, we want the original viewproj matrix _without_ the custom near clip plane.
+        // since all we are interested in is depth, we only need the third row of the matrix.
+        Ogre::Matrix4 projMatrix = mCamera->getProjectionMatrixWithRSDepth () * mCamera->getViewMatrix ();
+        sh::Vector4* row3 = new sh::Vector4(projMatrix[2][0], projMatrix[2][1], projMatrix[2][2], projMatrix[2][3]);
+        sh::Factory::getInstance ().setSharedParameter ("vpRow2Fix", sh::makeProperty<sh::Vector4> (row3));
+
         // enable clip plane here to take advantage of CPU culling for overwater or underwater objects
         mCamera->enableCustomNearClipPlane(mIsUnderwater ? mNearClipPlaneUnderwater : mNearClipPlane);
 
@@ -62,6 +70,7 @@ namespace MWRender
 
     void Refraction::postRenderTargetUpdate(const Ogre::RenderTargetEvent& evt)
     {
+        mCamera->disableCustomNearClipPlane ();
         mRenderActive = false;
     }
 

apps/openmw/mwrender/renderingmanager.cpp

@@ -140,6 +140,8 @@ RenderingManager::RenderingManager (OEngine::Render::OgreRenderer& _rend, const
     sh::Factory::getInstance ().setSharedParameter ("windDir_windSpeed", sh::makeProperty<sh::Vector3>(new sh::Vector3(0.5, -0.8, 0.2)));
     sh::Factory::getInstance ().setSharedParameter ("waterSunFade_sunHeight", sh::makeProperty<sh::Vector2>(new sh::Vector2(1, 0.6)));
     sh::Factory::getInstance ().setGlobalSetting ("refraction", Settings::Manager::getBool("refraction", "Water") ? "true" : "false");
+    sh::Factory::getInstance ().setGlobalSetting ("viewproj_fix", "false");
+    sh::Factory::getInstance ().setSharedParameter ("vpRow2Fix", sh::makeProperty<sh::Vector4> (new sh::Vector4(0,0,0,0)));
 
     applyCompositors();
 

apps/openmw/mwrender/water.cpp

@@ -144,6 +144,12 @@ void PlaneReflection::preRenderTargetUpdate(const Ogre::RenderTargetEvent& evt)
     mSky->setSkyPosition(pos);
     mCamera->enableReflection(mWaterPlane);
 
+    // for depth calculation, we want the original viewproj matrix _without_ the custom near clip plane.
+    // since all we are interested in is depth, we only need the third row of the matrix.
+    Ogre::Matrix4 projMatrix = mCamera->getProjectionMatrixWithRSDepth () * mCamera->getViewMatrix ();
+    sh::Vector4* row3 = new sh::Vector4(projMatrix[2][0], projMatrix[2][1], projMatrix[2][2], projMatrix[2][3]);
+    sh::Factory::getInstance ().setSharedParameter ("vpRow2Fix", sh::makeProperty<sh::Vector4> (row3));
+
     // enable clip plane here to take advantage of CPU culling for overwater or underwater objects
     mCamera->enableCustomNearClipPlane(mIsUnderwater ? mErrorPlaneUnderwater : mErrorPlane);
 }

files/materials/objects.shader

@@ -23,12 +23,21 @@
 
 #define VERTEX_LIGHTING 1
 
+#define VIEWPROJ_FIX @shGlobalSettingBool(viewproj_fix)
+
 #ifdef SH_VERTEX_SHADER
 
     // ------------------------------------- VERTEX ---------------------------------------
 
     SH_BEGIN_PROGRAM
         shUniform(float4x4, wvp) @shAutoConstant(wvp, worldviewproj_matrix)
+
+#if VIEWPROJ_FIX
+        shUniform(float4x4, worldMatrix) @shAutoConstant(worldMatrix, world_matrix)
+        shUniform(float4, vpRow2Fix) @shSharedParameter(vpRow2Fix, vpRow2Fix)
+        shUniform(float4x4, vpMatrix) @shAutoConstant(vpMatrix, viewproj_matrix)
+#endif
+
         shVertexInput(float2, uv0)
         shOutput(float2, UV)
         shNormalInput(float4)
@@ -65,7 +74,6 @@
 #if SHADOWS
         shOutput(float4, lightSpacePos0)
         shUniform(float4x4, texViewProjMatrix0) @shAutoConstant(texViewProjMatrix0, texture_viewproj_matrix)
-        shUniform(float4x4, worldMatrix) @shAutoConstant(worldMatrix, world_matrix)
 #endif
 
 #if SHADOWS_PSSM
@@ -73,8 +81,10 @@
         shOutput(float4, lightSpacePos@shIterator)
         shUniform(float4x4, texViewProjMatrix@shIterator) @shAutoConstant(texViewProjMatrix@shIterator, texture_viewproj_matrix, @shIterator)
     @shEndForeach
+#if !VIEWPROJ_FIX
     shUniform(float4x4, worldMatrix) @shAutoConstant(worldMatrix, world_matrix)
 #endif
+#endif
 
 #if VERTEX_LIGHTING
     shOutput(float3, lightResult)
@@ -89,9 +99,28 @@
 #endif
 
 #ifdef NEED_DEPTH
+
+
+#if VIEWPROJ_FIX
+        float4x4 vpFixed = vpMatrix;
+#if !SH_GLSL
+        vpFixed[2] = vpRow2Fix;
+#else
+        vpFixed[0][2] = vpRow2Fix.x;
+        vpFixed[1][2] = vpRow2Fix.y;
+        vpFixed[2][2] = vpRow2Fix.z;
+        vpFixed[3][2] = vpRow2Fix.w;
+#endif
+
+        float4x4 fixedWVP = shMatrixMult(vpFixed, worldMatrix);
+
+        depthPassthrough = shMatrixMult(fixedWVP, shInputPosition).z;
+#else
         depthPassthrough = shOutputPosition.z;
 #endif
 
+#endif
+
 #if LIGHTING
         objSpacePositionPassthrough = shInputPosition.xyz;
 #endif

files/materials/openmw.configuration

@@ -1,8 +1,13 @@
 configuration water_reflection
 {
-    fog false
     shadows false
     shadows_pssm false
+    viewproj_fix true
+}
+
+configuration water_refraction
+{
+    viewproj_fix true
 }
 
 configuration local_map

files/materials/terrain.shader

@@ -23,6 +23,8 @@
 
 #define UNDERWATER @shGlobalSettingBool(underwater_effects) && LIGHTING
 
+#define VIEWPROJ_FIX @shGlobalSettingBool(viewproj_fix)
+
 
 #if NEED_DEPTH
 @shAllocatePassthrough(1, depth)
@@ -51,6 +53,10 @@
         shUniform(float4x4, worldMatrix) @shAutoConstant(worldMatrix, world_matrix)
         shUniform(float4x4, viewProjMatrix) @shAutoConstant(viewProjMatrix, viewproj_matrix)
         
+#if VIEWPROJ_FIX
+        shUniform(float4, vpRow2Fix) @shSharedParameter(vpRow2Fix, vpRow2Fix)
+#endif
+
         shUniform(float2, lodMorph) @shAutoConstant(lodMorph, custom, 1001)
         
         shVertexInput(float2, uv0)
@@ -94,7 +100,25 @@
         shOutputPosition = shMatrixMult(viewProjMatrix, worldPos);
         
 #if NEED_DEPTH
+#if VIEWPROJ_FIX
+        float4x4 vpFixed = viewProjMatrix;
+#if !SH_GLSL
+        vpFixed[2] = vpRow2Fix;
+#else
+        vpFixed[0][2] = vpRow2Fix.x;
+        vpFixed[1][2] = vpRow2Fix.y;
+        vpFixed[2][2] = vpRow2Fix.z;
+        vpFixed[3][2] = vpRow2Fix.w;
+#endif
+
+        float4x4 fixedWVP = shMatrixMult(vpFixed, worldMatrix);
+
+        float depth = shMatrixMult(fixedWVP, shInputPosition).z;
+        @shPassthroughAssign(depth, depth);
+#else
         @shPassthroughAssign(depth, shOutputPosition.z);
+#endif
+
 #endif
 
         @shPassthroughAssign(UV, uv0);