Adding support for controlling visual settings via environmental variables

and command line paramters.  Including support for stereo and stencil buffer.

src/osgDB/ReadFile.cpp

@@ -2,6 +2,7 @@
 #include <osg/Object>
 #include <osg/Image>
 #include <osg/Node>
+#include <osg/Group>
 
 #include <osgDB/Registry>
 #include <osgDB/ReadFile>
@@ -34,3 +35,52 @@ Node* osgDB::readNodeFile(const std::string& filename)
     if (rr.error()) notify(WARN) << rr.message() << std::endl;
     return NULL;
 }
+
+Node* osgDB::readNodeFiles(std::vector<std::string>& commandLine)
+{
+    typedef std::vector<osg::Node*> NodeList;
+    NodeList nodeList;
+
+    // note currently doesn't delete the loaded files yet...
+
+    for(std::vector<std::string>::iterator itr=commandLine.begin();
+        itr!=commandLine.end();
+        ++itr)
+    {
+        if ((*itr)[0]!='-')
+        {
+            // not an option so assume string is a filename.
+            osg::Node *node = osgDB::readNodeFile( *itr );
+
+            if( node != (osg::Node *)0L )
+            {
+                if (node->getName().empty()) node->setName( *itr );
+                nodeList.push_back(node);
+            }
+
+        }
+    }
+    
+    if (nodeList.empty())
+    {
+        return NULL;
+    }
+
+    if (nodeList.size()==1)
+    {
+        return nodeList.front();
+    }
+    else  // size >1
+    {
+        osg::Group* group = new osg::Group();
+        for(NodeList::iterator itr=nodeList.begin();
+            itr!=nodeList.end();
+            ++itr)
+        {
+            group->addChild(*itr);
+        }
+
+        return group;
+    }
+    
+}