From Jean-Sebastien Guay, replaced M_PI with osg::PI.
From Jean-Sebastien Guay, replaced M_PI with osg::PI.


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