Reduce the number of osg::Material state by setting the default state on the graph root

apps/opencs/view/render/scenewidget.cpp

@@ -10,6 +10,7 @@
 #include <osgViewer/CompositeViewer>
 #include <osgViewer/ViewerEventHandlers>
 #include <osg/LightModel>
+#include <osg/Material>
 #include <osg/Version>
 
 #include <components/resource/scenemanager.hpp>
@@ -74,6 +75,12 @@ RenderWidget::RenderWidget(QWidget *parent, Qt::WindowFlags f)
 
     mView->getCamera()->getOrCreateStateSet()->setMode(GL_NORMALIZE, osg::StateAttribute::ON);
     mView->getCamera()->getOrCreateStateSet()->setMode(GL_CULL_FACE, osg::StateAttribute::ON);
+    osg::ref_ptr<osg::Material> defaultMat (new osg::Material);
+    defaultMat->setColorMode(osg::Material::OFF);
+    defaultMat->setAmbient(osg::Material::FRONT_AND_BACK, osg::Vec4f(1,1,1,1));
+    defaultMat->setDiffuse(osg::Material::FRONT_AND_BACK, osg::Vec4f(1,1,1,1));
+    defaultMat->setSpecular(osg::Material::FRONT_AND_BACK, osg::Vec4f(0.f, 0.f, 0.f, 0.f));
+    mView->getCamera()->getOrCreateStateSet()->getOrCreateStateSet()->setAttribute(defaultMat);
 
     mView->setSceneData(mRootNode);
 

apps/openmw/mwrender/renderingmanager.cpp

@@ -6,6 +6,7 @@
 #include <osg/Light>
 #include <osg/LightModel>
 #include <osg/Fog>
+#include <osg/Material>
 #include <osg/PolygonMode>
 #include <osg/Group>
 #include <osg/UserDataContainer>
@@ -221,6 +222,12 @@ namespace MWRender
         sceneRoot->getOrCreateStateSet()->setMode(GL_CULL_FACE, osg::StateAttribute::ON);
         sceneRoot->getOrCreateStateSet()->setMode(GL_LIGHTING, osg::StateAttribute::ON);
         sceneRoot->getOrCreateStateSet()->setMode(GL_NORMALIZE, osg::StateAttribute::ON);
+        osg::ref_ptr<osg::Material> defaultMat (new osg::Material);
+        defaultMat->setColorMode(osg::Material::OFF);
+        defaultMat->setAmbient(osg::Material::FRONT_AND_BACK, osg::Vec4f(1,1,1,1));
+        defaultMat->setDiffuse(osg::Material::FRONT_AND_BACK, osg::Vec4f(1,1,1,1));
+        defaultMat->setSpecular(osg::Material::FRONT_AND_BACK, osg::Vec4f(0.f, 0.f, 0.f, 0.f));
+        sceneRoot->getOrCreateStateSet()->setAttribute(defaultMat);
 
         sceneRoot->setNodeMask(Mask_Scene);
         sceneRoot->setName("Scene Root");

components/nifosg/nifloader.cpp

@@ -1758,6 +1758,15 @@ namespace NifOsg
                 mat->setColorMode(osg::Material::AMBIENT);
             }
 
+            if (mat->getColorMode() == osg::Material::OFF
+                    && mat->getDiffuse(osg::Material::FRONT_AND_BACK) == osg::Vec4f(1,1,1,1)
+                    && mat->getAmbient(osg::Material::FRONT_AND_BACK) == osg::Vec4f(1,1,1,1)
+                    && mat->getSpecular(osg::Material::FRONT_AND_BACK) == osg::Vec4f(0.f, 0.f, 0.f, 0.f))
+            {
+                // default state, skip
+                return;
+            }
+
             // TODO: this could be replaced by a more generic mechanism of sharing any type of State Attribute
             // apply only for Materials for now
             mat = shareMaterial(mat);