//------------------------------------------------------------------------------------------//
//MainHeader.h
//------------------------------------------------------------------------------------------//
#pragma once

#ifndef MAINHEADER_H
#define MAINHEADER_H

#include "windows.h"
#include <commctrl.h>
#include <string.h>
#include <tchar.h>
#include "stdlib.h"
#include "stdio.h"
#include "math.h"
...
#pragma comment (lib,"opengl32.lib")
#pragma comment (lib,"glu32.lib")
#include <gl\gl.h>          // Header File For The OpenGL32 Library
#include <gl\glu.h>         // Header File For The GLu32 Library
...
using namespace std;
#include "Simulator.h"
#include "Camera.h"
#include "Objects.h"

#endif
//------------------------------------------------------------------------------------------//
//CORE.cpp
//------------------------------------------------------------------------------------------//
#include "MainHeader.h"
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{ ... }
...

//------------------------------------------------------------------------------------------//
//Camera.h
//------------------------------------------------------------------------------------------//
#include "Objects.h"
class Camera
{ ...
 void Render(void);
...}

//------------------------------------------------------------------------------------------//
//Camera.cpp
//------------------------------------------------------------------------------------------//
#include "Camera.h"
void Camera::Render()
{...
gluLookAt(Position.x,Position.y,Position.z,     // Вот тут выдает ошибку: error C3861: 'gluLookAt': identifier not found
        ViewPoint.x,ViewPoint.y,ViewPoint.z,
        UpVector.x,UpVector.y,UpVector.z);
...
}