Fixed unused parameter warning.
Fixed unused parameter warning.

jtorresfabra/osg,scrawl/osg,openscenegraph/osg,scrawl/osg,artoolkit/osg,tomasthoresen/osg,marchelbling/osg,marchelbling/osg,tomasthoresen/osg,scrawl/osg,openscenegraph/osg,artoolkit/osg,tomasthoresen/osg,openscenegraph/osg,openscenegraph/osg,jtorresfabra/osg,jtorresfabra/osg,artoolkit/osg,marchelbling/osg,scrawl/osg,artoolkit/osg,jtorresfabra/osg,marchelbling/osg,tomasthoresen/osg