gluLookkAt should work but does not

Hi,

I came across a fool proof method for setting up gluLookAt but it has not worked for me. ( https://www.opengl.org/archives/resources/faq/technical/viewing.htm):
It suggested that all the data should fit inside a circle.

GLdouble left = c.x - diam;
GLdouble right = c.x + diam;
GLdouble bottom c.y - diam;
GLdouble top = c.y + diam;

glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(left, right, bottom, top, zNear, zFar);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();

GLdouble aspect = (GLdouble) windowWidth / windowHeight;

if ( aspect < 1.0 ) { // window taller than wide
bottom /= aspect;
top /= aspect;
} else {
left *= aspect;
right *= aspect;
}
The above code should position the objects in your scene appropriately. If you intend to manipulate (i.e. rotate, etc.), you need to add a viewing transform to it.

A typical viewing transform will go on the ModelView matrix and might look like this:

GluLookAt (0., 0., 2.*diam,
c.x, c.y, c.z,
0.0, 1.0, 0.0);

Is it because I am getting the coordinates of a mapping system confused with the coordinates of the graphics system confused? Any help gratefully appreciated.

MacSam



//Circle() returns the centre of the circle and the radius.
//123
	 cirCentre = Circle( 
		 e_3dMin,//1
		 n_3dMin,
		 e_3dMin,//2
		 n_3dMax,
		 e_3dMax,//3
		 n_3dMax);
	 //check 4 is it inside or outside of the circle
	 dRadius = sqrt((cirCentre.dEast - e_3dMax ) * (cirCentre.dEast - e_3dMax ) + (cirCentre.dNorth - n_3dMin ) * (cirCentre.dNorth - n_3dMin )) ;

	 if( dRadius > cirCentre.dRadiusSq )
	 {
		 //124
		 cirCentre = Circle( 
		 e_3dMin,//1
		 n_3dMin,
		 e_3dMin,//2
		 n_3dMax,
		 e_3dMax,//4
		 n_3dMin
		 );
		 //check 3
		 dRadius = sqrt((cirCentre.dEast - e_3dMax ) * (cirCentre.dEast - e_3dMax ) + (cirCentre.dNorth - n_3dMax ) * (cirCentre.dNorth - n_3dMax ));

		 if( dRadius > cirCentre.dRadiusSq )
		{
			//2 3 4
			cirCentre = Circle( 
				e_3dMin,//2
				n_3dMax,
				e_3dMax,//3
				 n_3dMax,
				e_3dMax,//4
				n_3dMin
				
				);
			//check 1
			dRadius = sqrt((cirCentre.dEast - e_3dMin ) * (cirCentre.dEast - e_3dMin ) + (cirCentre.dNorth - n_3dMin ) * (cirCentre.dNorth - n_3dMin ));

			 if( dRadius > cirCentre.dRadiusSq )
			 {
				 //3 4 1
				cirCentre = Circle( 
						e_3dMax,//3
						n_3dMax,
						e_3dMax,//4
						n_3dMin, 
						e_3dMin,//1
						n_3dMin
					);
			//check 2
				dRadius = sqrt((cirCentre.dEast - e_3dMin ) * (cirCentre.dEast - e_3dMin ) + (cirCentre.dNorth - n_3dMax ) * (cirCentre.dNorth - n_3dMax ));

				if( dRadius > cirCentre.dRadiusSq )
				{
				//error
				MessageBox (hwndThrd, "Error centering model",
                         "qwerty", MB_ICONASTERISK );    
				}

			 }

		 }


	 }

	 
	gldLeft = (GLdouble)(cirCentre.dEast - 2.*(cirCentre.dRadiusSq ));
	gldRight = (GLdouble)(cirCentre.dEast + 2.*(cirCentre.dRadiusSq ));
	gldTop = (GLdouble)(cirCentre.dNorth + 2.*(cirCentre.dRadiusSq ));
	gldBottom = (GLdouble)(cirCentre.dNorth - 2.*(cirCentre.dRadiusSq ));
	glFar = (GLdouble)cirCentre.dRadiusSq;

	if( gldAspect < 1.0 )
	{
		gldBottom /= gldAspect;
		gldTop /= gldAspect;
	}
	else
	{
		gldLeft *= gldAspect;
		gldRight *= gldAspect;
	}


	glScaled( 1.0, 1.0, 1.0 );
	

	
	glOrtho( (GLdouble)gldLeft, (GLdouble)gldRight, (GLdouble)gldTop, (GLdouble)gldBottom, -4.* glFar, 4.*glFar);


	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();


	gluLookAt(0.0,4.*glFar, 0.0,  cirCentre.dEast, cirCentre.dNorth, 0.0, 0.0, 0.0, -1.0);