rem: OSGMatrix m;
add: Matrix m;
context: display(void){    float a = glutGet( GLUT_ELAPSED_TIME );    if ( (int) ( a / 2000 ) & 1 )           glPolygonMode( GL_FRONT_AND_BACK, GL_LINE );    else        glPolygonMode( GL_FRONT_AND_BACK, GL_FILL );    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );    OSGMatrix m;    m.setTranslate( 0,0,sin(a/1500) * 2 );    osgBeginEditCP(tr);    tr->getSFMatrix()->setValue( m );    osgEndEditCP(tr);        dact->apply( root );    glutSwapBuffers();}