OSG::NodeTransitPtr makeScene( void )
{
    setupDefaultMaterial();

    OSG::NodeTransitPtr         root    = OSG::Node            ::create();
    OSG::SurfaceRefPtr          surface = OSG::Surface         ::create();
    OSG::GeoPnt3fPropertyRefPtr cps     = OSG::GeoPnt3fProperty::create();

    // control points should always be 3D for the time being,
    // rational support will be added later
    cps->clear();
    cps->push_back( OSG::Pnt3f(  1,  1,  2 ));
    cps->push_back( OSG::Pnt3f(  1,  0,  0 ));
    cps->push_back( OSG::Pnt3f(  1,  0,  1 ));
    cps->push_back( OSG::Pnt3f(  1, -1, -2 ));

    cps->push_back( OSG::Pnt3f(  0,  1,  0 ));
    cps->push_back( OSG::Pnt3f(  0,  0,  0 ));
    cps->push_back( OSG::Pnt3f(  0,  0,  1 ));
    cps->push_back( OSG::Pnt3f(  0, -1,  1 ));

    cps->push_back( OSG::Pnt3f(  0,  1,  1 ));
    cps->push_back( OSG::Pnt3f(  0,  0,  1 ));
    cps->push_back( OSG::Pnt3f(  0,  0,  0 ));
    cps->push_back( OSG::Pnt3f(  0, -1,  0 ));

    cps->push_back( OSG::Pnt3f( -1,  1,  1 ));
    cps->push_back( OSG::Pnt3f( -1,  0,  1 ));
    cps->push_back( OSG::Pnt3f( -1,  0,  0 ));
    cps->push_back( OSG::Pnt3f( -1, -1,  0 ));

    // let's clear the trimming
    surface->removeCurves();

    // set up dimensions and knot vectors:
    surface->setDimU( 3 );
    surface->setDimV( 3 );
    surface->editMFKnotsU()->clear();
    surface->editMFKnotsU()->push_back( 0 );
    surface->editMFKnotsU()->push_back( 0 );
    surface->editMFKnotsU()->push_back( 0 );
    surface->editMFKnotsU()->push_back( 0 );
    surface->editMFKnotsU()->push_back( 1 );
    surface->editMFKnotsU()->push_back( 1 );
    surface->editMFKnotsU()->push_back( 1 );
    surface->editMFKnotsU()->push_back( 1 );
    surface->editMFKnotsV()->clear();
    surface->editMFKnotsV()->push_back( 0 );
    surface->editMFKnotsV()->push_back( 0 );
    surface->editMFKnotsV()->push_back( 0 );
    surface->editMFKnotsV()->push_back( 0 );
    surface->editMFKnotsV()->push_back( 1 );
    surface->editMFKnotsV()->push_back( 1 );
    surface->editMFKnotsV()->push_back( 1 );
    surface->editMFKnotsV()->push_back( 1 );
    
    // set control points and texture control points
    surface->setControlPoints( cps );
    
    // set error
    surface->setError( g_error );
    
    // and finally set the material
    surface->setMaterial( gpcl_defaultmat );

    root->setCore( surface );

    gpcl_surface = surface;
    
    // Usually when the endEditCP() is called for an OSGSurface object
    // the need for (re)tessellation is flagged, and when the object
    // would be drawn on screen it gets tessellated. This might cause 
    // problems in a cluster environment as surfaces may get tessellated
    // more than once (e.g. on the server and on each client) which can
    // be _very_ slow and annoying.
    // 
    // The solution is "forcing" the tessellation by calling
    // OSGSurface::forceTessellate(). This will perform the tessellation
    // immediately, and setup flags so that automatic tessellation will
    // not be called again. This means that even if you change some or
    // all of the surface descriptiong FieldContainersin your OSGSurface
    // object it will _not_ be retessellated. You will have to "force"
    // tessellation again by calling OSGSurface::forceTessellate() whenever
    // you change something. See the calls in the keyboard() function
    // above.
    //
    // If you don't do clustering, you can probably just forget about all
    // this OSGSurface::forceTessellate() stuff (just like in the other 
    // Surface examples), it will just work automagically and tessellate 
    // your surface when needed (provided you don't forget the proper 
    // beginEditCP()/endEditCP() calls.
    if(useForceTesselate)
        gpcl_surface->forceTessellate();

    return root;
}
OSG::NodeTransitPtr makeScene( void )
{
    setupDefaultMaterial();

    OSG::NodeTransitPtr         root    = OSG::Node            ::create();
    OSG::SurfaceRefPtr          surface = OSG::Surface         ::create();
    OSG::GeoPnt3fPropertyRefPtr cps     = OSG::GeoPnt3fProperty::create();

    // control points should always be 3D for the time being,
    // rational support will be added later
    cps->clear();
    cps->push_back( OSG::Pnt3f(  1,  1,  0 ));
    cps->push_back( OSG::Pnt3f(  1,  0,  0 ));
    cps->push_back( OSG::Pnt3f(  1,  0,  1 ));
    cps->push_back( OSG::Pnt3f(  1, -1,  1 ));

    cps->push_back( OSG::Pnt3f(  0,  1,  0 ));
    cps->push_back( OSG::Pnt3f(  0,  0,  0 ));
    cps->push_back( OSG::Pnt3f(  0,  0,  1 ));
    cps->push_back( OSG::Pnt3f(  0, -1,  1 ));

    cps->push_back( OSG::Pnt3f(  0,  1,  1 ));
    cps->push_back( OSG::Pnt3f(  0,  0,  1 ));
    cps->push_back( OSG::Pnt3f(  0,  0,  0 ));
    cps->push_back( OSG::Pnt3f(  0, -1,  0 ));

    cps->push_back( OSG::Pnt3f( -1,  1,  1 ));
    cps->push_back( OSG::Pnt3f( -1,  0,  1 ));
    cps->push_back( OSG::Pnt3f( -1,  0,  0 ));
    cps->push_back( OSG::Pnt3f( -1, -1,  0 ));
    
    std::vector<OSG::Real64> knots1;
    std::vector<OSG::Real64> knots2;
    std::vector<OSG::Pnt2f> points;
    knots1.clear();
    knots1.push_back(0);
    knots1.push_back(0);
    knots1.push_back(1);
    knots1.push_back(1);
    knots2.clear();
    knots2.push_back(0);
    knots2.push_back(0);
    knots2.push_back(0);
    knots2.push_back(1);
    knots2.push_back(1);
    knots2.push_back(1);
        
    // first, let's clear the trimming
    surface->removeCurves();

    // add the outer trimming around the domain
    points.clear();
    points.push_back( OSG::Pnt2f(0,0) );
    points.push_back( OSG::Pnt2f(1,0) );
    surface->addCurve( 1, knots1, points, true );
    points.clear();
    points.push_back( OSG::Pnt2f(1,0) );
    points.push_back( OSG::Pnt2f(1,1) );
    surface->addCurve( 1, knots1, points, false );
    points.clear();
    points.push_back( OSG::Pnt2f(1,1) );
    points.push_back( OSG::Pnt2f(0,1) );
    surface->addCurve( 1, knots1, points, false );
    points.clear();
    points.push_back( OSG::Pnt2f(0,1) );
    points.push_back( OSG::Pnt2f(0,0) );
    surface->addCurve( 1, knots1, points, false );

    // add inner trimming loop 1
    points.clear();
    points.push_back( OSG::Pnt2f(0.3f,0.5f) );
    points.push_back( OSG::Pnt2f(0.1f,0.9f) );
    points.push_back( OSG::Pnt2f(0.5f,0.7f) );
    surface->addCurve( 2, knots2, points, true );
    points.clear();
    points.push_back( OSG::Pnt2f(0.5f,0.7f) );
    points.push_back( OSG::Pnt2f(0.9f,0.9f) );
    points.push_back( OSG::Pnt2f(0.7f,0.5f) );
    surface->addCurve( 2, knots2, points, false );
    points.clear();
    points.push_back( OSG::Pnt2f(0.7f,0.5f) );
    points.push_back( OSG::Pnt2f(0.9f,0.1f) );
    points.push_back( OSG::Pnt2f(0.5f,0.3f) );
    surface->addCurve( 2, knots2, points, false );
    points.clear();
    points.push_back( OSG::Pnt2f(0.5f,0.3f) );
    points.push_back( OSG::Pnt2f(0.1f,0.1f) );
    points.push_back( OSG::Pnt2f(0.3f,0.5f) );
    surface->addCurve( 2, knots2, points, false );
    
    // add inner trimming loop 2
    points.clear();
    points.push_back( OSG::Pnt2f(0.4f,0.5f) );
    points.push_back( OSG::Pnt2f(0.4f,0.4f) );
    points.push_back( OSG::Pnt2f(0.5f,0.4f) );
    surface->addCurve( 2, knots2, points, true );
    points.clear();
    points.push_back( OSG::Pnt2f(0.5f,0.4f) );
    points.push_back( OSG::Pnt2f(0.6f,0.4f) );
    points.push_back( OSG::Pnt2f(0.6f,0.5f) );
    surface->addCurve( 2, knots2, points, false );
    points.clear();
    points.push_back( OSG::Pnt2f(0.6f,0.5f) );
    points.push_back( OSG::Pnt2f(0.6f,0.6f) );
    points.push_back( OSG::Pnt2f(0.5f,0.6f) );
    surface->addCurve( 2, knots2, points, false );
    points.clear();
    points.push_back( OSG::Pnt2f(0.5f,0.6f) );
    points.push_back( OSG::Pnt2f(0.4f,0.6f) );
    points.push_back( OSG::Pnt2f(0.4f,0.5f) );
    surface->addCurve( 2, knots2, points, false );
    
    // set up dimensions and knot vectors:
    surface->setDimU( 3 );
    surface->setDimV( 3 );
    surface->editMFKnotsU()->clear();
    surface->editMFKnotsU()->push_back( 0 );
    surface->editMFKnotsU()->push_back( 0 );
    surface->editMFKnotsU()->push_back( 0 );
    surface->editMFKnotsU()->push_back( 0 );
    surface->editMFKnotsU()->push_back( 1 );
    surface->editMFKnotsU()->push_back( 1 );
    surface->editMFKnotsU()->push_back( 1 );
    surface->editMFKnotsU()->push_back( 1 );
    surface->editMFKnotsV()->clear();
    surface->editMFKnotsV()->push_back( 0 );
    surface->editMFKnotsV()->push_back( 0 );
    surface->editMFKnotsV()->push_back( 0 );
    surface->editMFKnotsV()->push_back( 0 );
    surface->editMFKnotsV()->push_back( 1 );
    surface->editMFKnotsV()->push_back( 1 );
    surface->editMFKnotsV()->push_back( 1 );
    surface->editMFKnotsV()->push_back( 1 );
    
    // set control points and texture control points
    surface->setControlPoints( cps );
    
    // set error
    surface->setError( g_error );
    
    // and finally set the material
    surface->setMaterial( gpcl_defaultmat );

    root->setCore( surface );

    gpcl_surface = surface;

    return root;
}