void Application::mainLoop( float fps )
{
// ...
        h3dRender( _cam );

        glColor3f(1.0f, 1.0f, 1.0f);
   glBegin(GL_LINES);

   glVertex3f(0, 0, 0); // origin of the line
   glVertex3f(0, 10000, 0); // ending point of the line
   glEnd( );
}

void Application::pick(float dX, float dY) {
   H3DNode node = h3dutPickNode(_cam, dX, dY);
   //h3dSetNodeActivation(node, false);
   curnode_ = node;
}

void Application::mainLoop( float fps )
{
       // skipped sample code...
   h3dRender( _cam );

   DrawBoundingBox();
}
void Application::DrawBoundingBox() {
   if (curnode_) {
      const float* camera = 0;
      // Retrieve camera position...     
      h3dGetNodeTransMats(_cam, 0, &camera);   

      // In case of an invalid camera (e.g. pipeline not set) return   
      if ( !camera ) return;   

      // ... and projection matrix
      float projMat[16];
      h3dGetCameraProjMat( _cam, projMat );

      // ...

      // Set projection matrix
      glMatrixMode( GL_PROJECTION );
      glLoadMatrixf( projMat );
      // apply camera transformation
      glMatrixMode( GL_MODELVIEW );
      Matrix4f transMat( camera );
      glLoadMatrixf( transMat.inverted().x );

      // then later in e.g. drawGizmo

      glPushMatrix();

      const float *nodeTransform = 0;
      h3dGetNodeTransMats(curnode_, NULL, &nodeTransform);
      glMultMatrixf(nodeTransform);   // Load scene node matrix

      // ... draw code

      float minX, minY, minZ, maxX, maxY, maxZ;
      h3dGetNodeAABB(curnode_, &minX, &minY, &minZ, &maxX, &maxY, &maxZ);
      glColor3f(0.7f, 0.7f, 0.7f);
      glBegin(GL_LINE_STRIP);
      glVertex3f(minX, minY, minZ);
      glVertex3f(maxX, minY, minZ);
      glVertex3f(maxX, maxY, minZ);
      glVertex3f(minX, maxY, minZ);
      glVertex3f(minX, minY, minZ);
      glVertex3f(minX, minY, maxZ);
      glVertex3f(maxX, minY, maxZ);
      glVertex3f(maxX, maxY, maxZ);
      glVertex3f(minX, maxY, maxZ);
      glVertex3f(minX, minY, maxZ);
      glEnd();
      glBegin(GL_LINES);
      glVertex3f(minX, maxY, minZ);
      glVertex3f(minX, maxY, maxZ);
      glVertex3f(maxX, minY, minZ);
      glVertex3f(maxX, minY, maxZ);
      glVertex3f(maxX, maxY, minZ);
      glVertex3f(maxX, maxY, maxZ);
      glEnd();

      glPopMatrix();
   }
}

paintGL()
{
    h3dRender(_cameraNode); // Render scene   

    if (cur_) {

        const float* camera = 0;
        h3dGetNodeTransMats(_cameraNode, 0, &camera);   
        if ( !camera ) return;
        float projMat[16];
        h3dGetCameraProjMat( _cameraNode, projMat );
        Matrix4f cam_matrix( camera );
        const float *nodeTransform = 0;
        h3dGetNodeTransMats(cur_, &nodeTransform, NULL);
       
        glMatrixMode( GL_MODELVIEW );
        glPushMatrix();
        glLoadMatrixf(cam_matrix.inverted().x);
        glMultMatrixf(nodeTransform);   // Load scene node matrix
       
        glMatrixMode( GL_PROJECTION );
        glPushMatrix();
        glLoadMatrixf( projMat );

        // ... draw code

        glPopMatrix();
        glMatrixMode( GL_MODELVIEW );
        glPopMatrix();
        }
}

       float minX, minY, minZ, maxX, maxY, maxZ;
        h3dGetNodeAABB(cur_, &minX, &minY, &minZ, &maxX, &maxY, &maxZ);
        glColor3f(0.7f, 0.7f, 0.7f);
        glBegin(GL_LINE_STRIP);
        glVertex3f(minX, minY, minZ);
        glVertex3f(maxX, minY, minZ);
        glVertex3f(maxX, maxY, minZ);
        glVertex3f(minX, maxY, minZ);
        glVertex3f(minX, minY, minZ);
        glVertex3f(minX, minY, maxZ);
        glVertex3f(maxX, minY, maxZ);
        glVertex3f(maxX, maxY, maxZ);
        glVertex3f(minX, maxY, maxZ);
        glVertex3f(minX, minY, maxZ);
        glEnd();
        glBegin(GL_LINES);
        glVertex3f(minX, maxY, minZ);
        glVertex3f(minX, maxY, maxZ);
        glVertex3f(maxX, minY, minZ);
        glVertex3f(maxX, minY, maxZ);
        glVertex3f(maxX, maxY, minZ);
        glVertex3f(maxX, maxY, maxZ);
        glEnd();

const float* camera = 0;

        h3dGetNodeTransMats(_cameraNode, 0, &camera);   
        if ( !camera ) return;
        Matrix4f cam_matrix( camera );

        glMatrixMode( GL_MODELVIEW );
        glPushMatrix();
        glLoadMatrixf(cam_matrix.inverted().x);

        float projMat[16];
        h3dGetCameraProjMat( _cameraNode, projMat );
       
        glMatrixMode( GL_PROJECTION );
        glPushMatrix();

        glLoadMatrixf( projMat);
        glMatrixMode( GL_MODELVIEW );

// opengl drawing code

        glMatrixMode( GL_PROJECTION );
        glPopMatrix();

        glMatrixMode( GL_MODELVIEW );
        glPopMatrix();

static float gPlaneData[]={
    -1.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f,
    1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, -1.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f,
    1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f
};

   glPushMatrix();
    glScalef(100,100,100);
    glEnableClientState(GL_VERTEX_ARRAY);
    glEnableClientState(GL_NORMAL_ARRAY);
    glVertexPointer(3, GL_FLOAT, 2*3*sizeof(float), gPlaneData);
    glNormalPointer(GL_FLOAT, 2*3*sizeof(float), gPlaneData+3);
    glDrawArrays(GL_TRIANGLES, 0, 6);
    glDisableClientState(GL_VERTEX_ARRAY);
    glDisableClientState(GL_NORMAL_ARRAY);

    glBegin(GL_LINES);
    glVertex3f(0,0,0);
    glVertex3f(1,1,1);
    glEnd();

    glPopMatrix();

glClearColor(1, 0, 0, 1);
glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);