Added hull="hul-filename" property support to <volume> tag that can u…

…sed thus:

        <layer>
            <volume renderer="MultiPass" hull="cow.osgt.0,-2,-4.trans.50,50,50.scale">CardiacCT</volume>
        </layer>

include/osgPresentation/deprecated/SlideShowConstructor

@@ -328,6 +328,7 @@ public:
         osg::ColorSpaceOperation                colorSpaceOperation;
         osg::Vec4                               colorModulate;
         Technique                               technique;
+        std::string                             hull;
     };
 
 

src/osgPlugins/p3d/ReaderWriterP3D.cpp

@@ -1307,6 +1307,12 @@ void ReaderWriterP3DXML::parseVolume(osgPresentation::SlideShowConstructor& cons
         else if (renderer=="MultiPass") volumeData.technique =  osgPresentation::SlideShowConstructor::VolumeData::MultiPass;
     }
 
+    std::string hull;
+    if (getProperty(cur, "hull", hull))
+    {
+        volumeData.hull = hull;
+    }
+
     if (getProperty(cur, "alpha", volumeData.alphaValue)) {}
     if (getProperty(cur, "cutoff", volumeData.cutoffValue)) {}
     if (getProperty(cur, "region", volumeData.region)) {}

src/osgPresentation/deprecated/SlideShowConstructor.cpp

@@ -2816,6 +2816,15 @@ void SlideShowConstructor::addVolume(const std::string& filename, const Position
         }
     }
 
+    if (!volumeData.hull.empty())
+    {
+        osg::ref_ptr<osg::Node> hull = osgDB::readNodeFile(volumeData.hull, _options.get());
+        if (hull.valid())
+        {
+            tile->addChild(hull);
+        }
+    }
+
 
     osg::ref_ptr<osg::Node> model = volume.get();