Implement a custom RenderBin for first person models (Fixes #1612)

apps/openmw/mwrender/animation.cpp

@@ -1275,15 +1275,26 @@ namespace MWRender
             material->setAmbient(osg::Material::FRONT_AND_BACK, osg::Vec4f(1,1,1,1));
             stateset->setAttributeAndModes(material, osg::StateAttribute::ON|osg::StateAttribute::OVERRIDE);
 
-            stateset->setRenderingHint(osg::StateSet::TRANSPARENT_BIN);
-            stateset->setRenderBinMode(osg::StateSet::OVERRIDE_RENDERBIN_DETAILS);
-            stateset->setNestRenderBins(false);
             mObjectRoot->setStateSet(stateset);
         }
         else
         {
             mObjectRoot->setStateSet(NULL);
         }
+
+        setRenderBin();
+    }
+
+    void Animation::setRenderBin()
+    {
+        if (mAlpha != 1.f)
+        {
+            osg::StateSet* stateset = mObjectRoot->getOrCreateStateSet();
+            stateset->setRenderingHint(osg::StateSet::TRANSPARENT_BIN);
+            stateset->setRenderBinMode(osg::StateSet::OVERRIDE_RENDERBIN_DETAILS);
+        }
+        else if (osg::StateSet* stateset = mObjectRoot->getStateSet())
+            stateset->setRenderBinToInherit();
     }
 
     void Animation::setLightEffect(float effect)

apps/openmw/mwrender/animation.hpp

@@ -307,6 +307,9 @@ protected:
 
     void addGlow(osg::ref_ptr<osg::Node> node, osg::Vec4f glowColor);
 
+    /// Set the render bin for this animation's object root. May be customized by subclasses.
+    virtual void setRenderBin();
+
 public:
 
     Animation(const MWWorld::Ptr &ptr, osg::ref_ptr<osg::Group> parentNode, Resource::ResourceSystem* resourceSystem);

apps/openmw/mwrender/npcanimation.cpp

@@ -2,6 +2,9 @@
 
 #include <osg/UserDataContainer>
 #include <osg/MatrixTransform>
+#include <osg/Depth>
+
+#include <osgUtil/RenderBin>
 
 #include <components/misc/rng.hpp>
 
@@ -28,6 +31,7 @@
 
 #include "camera.hpp"
 #include "rotatecontroller.hpp"
+#include "renderbin.hpp"
 
 namespace
 {
@@ -303,6 +307,50 @@ void NpcAnimation::setViewMode(NpcAnimation::ViewMode viewMode)
 
     mViewMode = viewMode;
     rebuild();
+
+    setRenderBin();
+}
+
+/// @brief A RenderBin callback to clear the depth buffer before rendering.
+class DepthClearCallback : public osgUtil::RenderBin::DrawCallback
+{
+public:
+    DepthClearCallback()
+    {
+        mDepth = new osg::Depth;
+        mDepth->setWriteMask(true);
+    }
+
+    virtual void drawImplementation(osgUtil::RenderBin* bin, osg::RenderInfo& renderInfo, osgUtil::RenderLeaf*& previous)
+    {
+        renderInfo.getState()->applyAttribute(mDepth);
+
+        glClear(GL_DEPTH_BUFFER_BIT);
+
+        bin->drawImplementation(renderInfo, previous);
+    }
+
+    osg::ref_ptr<osg::Depth> mDepth;
+};
+
+void NpcAnimation::setRenderBin()
+{
+    if (mViewMode == VM_FirstPerson)
+    {
+        static bool prototypeAdded = false;
+        if (!prototypeAdded)
+        {
+            osg::ref_ptr<osgUtil::RenderBin> depthClearBin (new osgUtil::RenderBin);
+            depthClearBin->setDrawCallback(new DepthClearCallback);
+            osgUtil::RenderBin::addRenderBinPrototype("DepthClear", depthClearBin);
+            prototypeAdded = true;
+        }
+
+        osg::StateSet* stateset = mObjectRoot->getOrCreateStateSet();
+        stateset->setRenderBinDetails(RenderBin_FirstPerson, "DepthClear", osg::StateSet::OVERRIDE_RENDERBIN_DETAILS);
+    }
+    else
+        Animation::setRenderBin();
 }
 
 void NpcAnimation::rebuild()

apps/openmw/mwrender/npcanimation.hpp

@@ -81,6 +81,8 @@ private:
     void addPartGroup(int group, int priority, const std::vector<ESM::PartReference> &parts,
                                     bool enchantedGlow=false, osg::Vec4f* glowColor=NULL);
 
+    virtual void setRenderBin();
+
     osg::ref_ptr<NeckController> mFirstPersonNeckController;
 
 protected:

apps/openmw/mwrender/renderbin.hpp

@@ -5,14 +5,15 @@ namespace MWRender
 {
 
     /// Defines the render bin numbers used in the OpenMW scene graph. The bin with the lowest number is rendered first.
-    /// Beware of RenderBin nesting, in most cases you will want to use setNestRenderBins(false).
     enum RenderBins
     {
         RenderBin_Sky = -1,
-        RenderBin_Default = 0,
+        RenderBin_Default = 0, // osg::StateSet::OPAQUE_BIN
         RenderBin_Water = 9,
-        RenderBin_OcclusionQuery = 10,
+        RenderBin_DepthSorted = 10, // osg::StateSet::TRANSPARENT_BIN
-        RenderBin_SunGlare = 11
+        RenderBin_OcclusionQuery = 11,
+        RenderBin_FirstPerson = 12,
+        RenderBin_SunGlare = 13
     };
 
 }