QGLWidget not displaying object as shown

Question

I am making a GUIon in Qt and I am using QGLWidgt to dispaly motion of an object. For debugging puposes, I hard coded on matrix for try to display a teapot, but nothing is showing up on the screen. I have tried many things, I just dont know what is wrong.

EDIT I figured out that it is showing the teapot, but the scaling is way off.. If i change the position was far from where it was. When I changed the position from -2.700, 2.000, 0.000 to -0.0270, 0.0200, 0.000, I could see it. I guess my question now is how to set the size of the screen to show what is being displayed??

The paintGL, resideGL and intializeGL are given below.

void GLWidget::initializeGL()

{
        glClearColor(1.0,1.0,1.0,1.0);
            GLUquadricObj *qobj = gluNewQuadric();  
        gluQuadricDrawStyle(qobj,GLU_FILL);
        gluQuadricNormals(qobj,GLU_SMOOTH); 
        glClearDepth( 1.0f );

        glEnable(GL_DEPTH_TEST);
        glShadeModel(GL_SMOOTH);
        double eqn[] = {0.01f,0.0f,0.01f,-1.0f};
        // enable clip plane    
        ::glClipPlane(GL_CLIP_PLANE0,eqn);

        setupLight();
    }

 void GLWidget::paintGL() {

        double MOpenGLStack[16] = {0.4314, 0.875, 0.2181, 0.000, 
                                   0.0567, -0.267, 0.961, 0.000,
                                   0.900, -0.402, -0.165, 0.000,
                                   -2.700, 2.000, 0.000, 1.000};

         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
         glMatrixMode(GL_MODELVIEW);
         glLoadIdentity();
          glTranslatef(0.0, 0.0, -5.0);
          glRotatef(xRot / 16.0, 1.0, 0.0, 0.0);
          glRotatef(yRot / 16.0, 0.0, 1.0, 0.0);
           glRotatef(zRot / 16.0, 0.0, 0.0, 1.0);
          glTranslated(xTrans / 16.0, yTrans/ 16.0, 0.0f);
         ::glPushMatrix();
        ::glMultMatrixd(MOpenGLStack);
          glutSolidTeapot(0.15);
        ::glPopMatrix();
    }


void GLWidget::resizeGL(int w, int h){

     int side = qMin(w, h);
     glViewport((w - side) / 2, (h - side) / 2, side, side);
     glMatrixMode(GL_PROJECTION);
     glLoadIdentity();
     gluPerspective(30.0f, (double)w/(double)h, 0.1f, 1000.0f);
     glOrtho(-0.5, +0.5, -0.5, +0.5, 4.0, 15.0);

     glMatrixMode(GL_MODELVIEW);
     glLoadIdentity ();
     glTranslatef(0.0f, 0.0f, -10.0f);
}

Answer 1

There is a problem here:

 gluPerspective(30.0f, (double)w/(double)h, 0.1f, 1000.0f);
 glOrtho(-0.5, +0.5, -0.5, +0.5, 4.0, 15.0);

The first line is overriden by the second line - you cannot have both perspective and orthographic view at the same time. If you do not want to view the teapot in parallel view, you can comment the second line.