   Dificult with opengl
  I am studying opengl through the tutoriais of the site using visual C++ 6.0. everything a marvel, until arriving in the lesson 10 -  Shipment and Moving in a world 3D - the such that has a type of cave ornamented by a mud texture with the a man''s image that repeats and that has 4 exit doors in black. I compiled and I usually rotated the code creating the executable. when they put I copy the code of the example for another project emptiness with the objetiovo of to do modifications in him and to learn independently when executing the project I receive the mistake message: " debug assertion failures ", already read the documentation of the msdn trying to solve the problem and anything. The worst is that the mistake message mentioned above says that the mistake this in a called file fgets.c, in the line 60, and that the mistake is in the expression " str!=NULL ". FOR GOD AS it can BE THAT A CALLED FILE it doesn''t EXIST FGETS.C IN MINE it PLANS (AND NOR IN THE PROJECT) AND MUCH LESS TO SUCH AN EXPRESSION IN MY PROJECT.    2. in the same tutorial I tried to alter the illumination. the idea is that when pressing a key any and to maintain it pressed the illumination would go gradually from the clearing to the darkness, when pressing other key any the effect it would be it I thwart. I tried to use the illumination knowledge obtained with previous tutoriais. Unhappily nào got the gradation: when pressing certain key and you loosen it I only get total light or any (everything black).    3. in the same example it would be interesting to get (for use in a screen protector for example) that the movement instead of being gotten with the keys of arrows and pageup and pagedown was automatic and I continue and it varied forward and back and for the sides and of bass upward.Thanked the whole ones that could help me at once.    Fábio   
  1. Probably you forgot to move the data directory along with the executable.  You need the texture and the world file to be in the same place relative to the executable.  So if you place the executable in ''c:\somefolder'' then you must place mud.bmp and World.txt in ''c:\somefolder\data''.2. Can you post the source code that you tried for this?Enigma ;  Dear Enigma once you were disposed to help it follows the code source:#include <stdlib.h>#include <windows.h>// Header File For Windows#include <math.h>// Math Library Header File#include <stdio.h>// Header File For Standard Input/Output#include <gl\gl.h>// Header File For The OpenGL32 Library#include <gl\glu.h>// Header File For The GLu32 Library#include <gl\glaux.h>// Header File For The Glaux LibraryHDChDC=NULL;// Private GDI Device ContextHGLRChRC=NULL;// Permanent Rendering ContextHWNDhWnd=NULL;// Holds Our Window HandleHINSTANCEhInstance;// Holds The Instance Of The Applicationboolkeys[256];// Array Used For The Keyboard Routineboolactive=TRUE;// Window Active Flag Set To TRUE By Defaultboolfullscreen=TRUE;// Fullscreen Flag Set To Fullscreen Mode By Defaultboolblend;// Blending ON/OFFboolbp;// B Pressed?boolfp;// F Pressed?const float piover180 = 0.0174532925f;float heading;float xpos;float zpos;GLfloatyrot;// Y RotationGLfloat walkbias = 0;GLfloat walkbiasangle = 0;GLfloat lookupdown = 0.0f;GLfloatz=0.0f;// Depth Into The ScreenGLuintfilter;// Which Filter To UseGLuinttexture[3];// Storage For 3 Texturestypedef struct tagVERTEX{float x, y, z;float u, v;} VERTEX;typedef struct tagTRIANGLE{VERTEX vertex[3];} TRIANGLE;typedef struct tagSECTOR{int numtriangles;TRIANGLE* triangle;} SECTOR;SECTOR sector1;// Our Model Goes Here:LRESULTCALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);// Declaration For WndProcvoid readstr(FILE *f,char *string){do{fgets(string, 255, f);} while ((string[0] == ''/'') || (string[0] == ''\n''));return;}void SetupWorld(){float x, y, z, u, v;int numtriangles;FILE *filein;char oneline[255];filein = fopen("data/world.txt", "rt");// File To Load World Data Fromreadstr(filein,oneline);sscanf(oneline, "NUMPOLLIES %d\n", &numtriangles);sector1.triangle = new TRIANGLE[numtriangles];sector1.numtriangles = numtriangles;for (int loop = 0; loop < numtriangles; loop++){for (int vert = 0; vert < 3; vert++){readstr(filein,oneline);sscanf(oneline, "%f %f %f %f %f", &x, &y, &z, &u, &v);sector1.triangle[loop].vertex[vert].x = x;sector1.triangle[loop].vertex[vert].y = y;sector1.triangle[loop].vertex[vert].z = z;sector1.triangle[loop].vertex[vert].u = u;sector1.triangle[loop].vertex[vert].v = v;}}fclose(filein);return;}AUX_RGBImageRec *LoadBMP(char *Filename) // Loads A Bitmap Image{   FILE *File=NULL;  // File Handle   if (!Filename)    // Make Sure A Filename Was Given   { return NULL;   // If Not Return NULL   }   File=fopen(Filename,"r");   // Check To See If The File Exists   if (File)    // Does The File Exist?   { fclose(File);  // Close The Handle return auxDIBImageLoad(Filename);  // Load The Bitmap And Return A Pointer   }   return NULL; // If Load Failed Return NULL}int LoadGLTextures() // Load Bitmaps And Convert To Textures{   int Status=FALSE; // Status Indicator   AUX_RGBImageRec *TextureImage[1];// Create Storage Space For The Texture   memset(TextureImage,0,sizeof(void *)*1);   // Set The Pointer To NULL   // Load The Bitmap, Check For Errors, If Bitmap''s Not Found Quit   if (TextureImage[0]=LoadBMP("Data/Mud.bmp"))   { Status=TRUE;   // Set The Status To TRUE glGenTextures(3, &texture[0]);// Create Three Textures// Create Nearest Filtered TextureglBindTexture(GL_TEXTURE_2D, texture[0]);glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);glTexImage2D(GL_TEXTURE_2D, 0, 3, TextureImage[0]->sizeX, TextureImage[0]->sizeY, 0, GL_RGB, GL_UNSIGNED_BYTE, TextureImage[0]->data); // Create Linear Filtered Texture glBindTexture(GL_TEXTURE_2D, texture[1]); glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR); glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR); glTexImage2D(GL_TEXTURE_2D, 0, 3, TextureImage[0]->sizeX, TextureImage[0]->sizeY, 0, GL_RGB, GL_UNSIGNED_BYTE, TextureImage[0]->data);// Create MipMapped TextureglBindTexture(GL_TEXTURE_2D, texture[2]);glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_NEAREST);gluBuild2DMipmaps(GL_TEXTURE_2D, 3, TextureImage[0]->sizeX, TextureImage[0]->sizeY, GL_RGB, GL_UNSIGNED_BYTE, TextureImage[0]->data);   }   if (TextureImage[0])   // If Texture Exists   { if (TextureImage[0]->data)    // If Texture Image Exists {   free(TextureImage[0]->data);    // Free The Texture Image Memory }free(TextureImage[0]);   // Free The Image Structure   }   return Status;    // Return The Status}GLvoid ReSizeGLScene(GLsizei width, GLsizei height)// Resize And Initialize The GL Window{if (height==0)// Prevent A Divide By Zero By{height=1;// Making Height Equal One}glViewport(0,0,width,height);// Reset The Current ViewportglMatrixMode(GL_PROJECTION);// Select The Projection MatrixglLoadIdentity();// Reset The Projection Matrix// Calculate The Aspect Ratio Of The WindowgluPerspective(45.0f,(GLfloat)width/(GLfloat)height,0.1f,100.0f);glMatrixMode(GL_MODELVIEW);// Select The Modelview MatrixglLoadIdentity();// Reset The Modelview Matrix}int InitGL(GLvoid)// All Setup For OpenGL Goes Here{if (!LoadGLTextures())// Jump To Texture Loading Routine{return FALSE;// If Texture Didn''t Load Return FALSE}glEnable(GL_TEXTURE_2D);// Enable Texture MappingglBlendFunc(GL_SRC_ALPHA,GL_ONE);// Set The Blending Function For TranslucencyglClearColor(0.0f, 0.0f, 0.0f, 0.0f);// This Will Clear The Background Color To BlackglClearDepth(1.0);// Enables Clearing Of The Depth BufferglDepthFunc(GL_LESS);// The Type Of Depth Test To DoglEnable(GL_DEPTH_TEST);// Enables Depth TestingglShadeModel(GL_SMOOTH);// Enables Smooth Color ShadingglHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);// Really Nice Perspective CalculationsSetupWorld();return TRUE;// Initialization Went OK}int DrawGLScene(GLvoid)// Here''s Where We Do All The Drawing{glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);// Clear The Screen And The Depth BufferglLoadIdentity();// Reset The ViewGLfloat x_m, y_m, z_m, u_m, v_m;GLfloat xtrans = -xpos;GLfloat ztrans = -zpos;GLfloat ytrans = -walkbias-0.25f;GLfloat sceneroty = 360.0f - yrot;int numtriangles;glRotatef(lookupdown,1.0f,0,0);glRotatef(sceneroty,0,1.0f,0); glTranslatef(xtrans, ytrans, ztrans);glBindTexture(GL_TEXTURE_2D, texture[filter]); numtriangles = sector1.numtriangles; // Process Each Trianglefor (int loop_m = 0; loop_m < numtriangles; loop_m++){glBegin(GL_TRIANGLES);glNormal3f( 0.0f, 0.0f, 1.0f);x_m = sector1.triangle[loop_m].vertex[0].x;y_m = sector1.triangle[loop_m].vertex[0].y;z_m = sector1.triangle[loop_m].vertex[0].z;u_m = sector1.triangle[loop_m].vertex[0].u;v_m = sector1.triangle[loop_m].vertex[0].v;glTexCoord2f(u_m,v_m); glVertex3f(x_m,y_m,z_m); x_m = sector1.triangle[loop_m].vertex[1].x;y_m = sector1.triangle[loop_m].vertex[1].y;z_m = sector1.triangle[loop_m].vertex[1].z;u_m = sector1.triangle[loop_m].vertex[1].u;v_m = sector1.triangle[loop_m].vertex[1].v;glTexCoord2f(u_m,v_m); glVertex3f(x_m,y_m,z_m); x_m = sector1.triangle[loop_m].vertex[2].x;y_m = sector1.triangle[loop_m].vertex[2].y;z_m = sector1.triangle[loop_m].vertex[2].z;u_m = sector1.triangle[loop_m].vertex[2].u;v_m = sector1.triangle[loop_m].vertex[2].v;glTexCoord2f(u_m,v_m); glVertex3f(x_m,y_m,z_m);glEnd();}return TRUE;// Everything Went OK}GLvoid KillGLWindow(GLvoid)// Properly Kill The Window{if (fullscreen)// Are We In Fullscreen Mode?{ChangeDisplaySettings(NULL,0);// If So Switch Back To The DesktopShowCursor(TRUE);// Show Mouse Pointer}if (hRC)// Do We Have A Rendering Context?{if (!wglMakeCurrent(NULL,NULL))// Are We Able To Release The DC And RC Contexts?{MessageBox(NULL,"Release Of DC And RC Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);}if (!wglDeleteContext(hRC))// Are We Able To Delete The RC?{MessageBox(NULL,"Release Rendering Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);}hRC=NULL;// Set RC To NULL}if (hDC && !ReleaseDC(hWnd,hDC))// Are We Able To Release The DC{MessageBox(NULL,"Release Device Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);hDC=NULL;// Set DC To NULL}if (hWnd && !DestroyWindow(hWnd))// Are We Able To Destroy The Window?{MessageBox(NULL,"Could Not Release hWnd.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);hWnd=NULL;// Set hWnd To NULL}if (!UnregisterClass("OpenGL",hInstance))// Are We Able To Unregister Class{MessageBox(NULL,"Could Not Unregister Class.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);hInstance=NULL;// Set hInstance To NULL}}/*This Code Creates Our OpenGL Window.  Parameters Are:* *title- Title To Appear At The Top Of The Window* *width- Width Of The GL Window Or Fullscreen Mode* *height- Height Of The GL Window Or Fullscreen Mode* *bits- Number Of Bits To Use For Color (8/16/24/32)* *fullscreenflag- Use Fullscreen Mode (TRUE) Or Windowed Mode (FALSE)*/ BOOL CreateGLWindow(char* title, int width, int height, int bits, bool fullscreenflag){GLuintPixelFormat;// Holds The Results After Searching For A MatchWNDCLASSwc;// Windows Class StructureDWORDdwExStyle;// Window Extended StyleDWORDdwStyle;// Window StyleRECTWindowRect;// Grabs Rectangle Upper Left / Lower Right ValuesWindowRect.left=(long)0;// Set Left Value To 0WindowRect.right=(long)width;// Set Right Value To Requested WidthWindowRect.top=(long)0;// Set Top Value To 0WindowRect.bottom=(long)height;// Set Bottom Value To Requested Heightfullscreen=fullscreenflag;// Set The Global Fullscreen FlaghInstance= GetModuleHandle(NULL);// Grab An Instance For Our Windowwc.style= CS_HREDRAW | CS_VREDRAW | CS_OWNDC;// Redraw On Size, And Own DC For Window.wc.lpfnWndProc= (WNDPROC) WndProc;// WndProc Handles Messageswc.cbClsExtra= 0;// No Extra Window Datawc.cbWndExtra= 0;// No Extra Window Datawc.hInstance= hInstance;// Set The Instancewc.hIcon= LoadIcon(NULL, IDI_WINLOGO);// Load The Default Iconwc.hCursor= LoadCursor(NULL, IDC_ARROW);// Load The Arrow Pointerwc.hbrBackground= NULL;// No Background Required For GLwc.lpszMenuName= NULL;// We Don''t Want A Menuwc.lpszClassName= "OpenGL";// Set The Class Nameif (!RegisterClass(&wc))// Attempt To Register The Window Class{MessageBox(NULL,"Failed To Register The Window Class.","ERROR",MB_OK|MB_ICONEXCLAMATION);return FALSE;// Return FALSE} if (fullscreen)// Attempt Fullscreen Mode?{DEVMODE dmScreenSettings;// Device Modememset(&dmScreenSettings,0,sizeof(dmScreenSettings));// Makes Sure Memory''s CleareddmScreenSettings.dmSize=sizeof(dmScreenSettings);// Size Of The Devmode StructuredmScreenSettings.dmPelsWidth= width;// Selected Screen WidthdmScreenSettings.dmPelsHeight= height;// Selected Screen HeightdmScreenSettings.dmBitsPerPel= bits;// Selected Bits Per PixeldmScreenSettings.dmFields=DM_BITSPERPEL|DM_PELSWIDTH|DM_PELSHEIGHT;// Try To Set Selected Mode And Get Results.  NOTE: CDS_FULLSCREEN Gets Rid Of Start Bar.if (ChangeDisplaySettings(&dmScreenSettings,CDS_FULLSCREEN)!=DISP_CHANGE_SUCCESSFUL){// If The Mode Fails, Offer Two Options.  Quit Or Use Windowed Mode.if (MessageBox(NULL,"The Requested Fullscreen Mode Is Not Supported By\nYour Video Card. Use Windowed Mode Instead?","NeHe GL",MB_YESNO|MB_ICONEXCLAMATION)==IDYES){fullscreen=FALSE;// Windowed Mode Selected.  Fullscreen = FALSE}else{// Pop Up A Message Box Letting User Know The Program Is Closing.MessageBox(NULL,"Program Will Now Close.","ERROR",MB_OK|MB_ICONSTOP);return FALSE;// Return FALSE}}}if (fullscreen)// Are We Still In Fullscreen Mode?{dwExnostyle=WS_EX_APPWINDOW;// Window Extended Styledwnostyle=WS_POPUP;// Windows StyleShowCursor(FALSE);// Hide Mouse Pointer}else{dwExnostyle=WS_EX_APPWINDOW | WS_EX_WINDOWEDGE;// Window Extended Styledwnostyle=WS_OVERLAPPEDWINDOW;// Windows Style}AdjustWindowRectEx(&WindowRect, dwStyle, FALSE, dwExStyle);// Adjust Window To True Requested Size// Create The Windowif (!(hWnd=CreateWindowEx(dwExStyle,// Extended Style For The Window"OpenGL",// Class Nametitle,// Window TitledwStyle |// Defined Window StyleWS_CLIPSIBLINGS |// Required Window StyleWS_CLIPCHILDREN,// Required Window Style0, 0,// Window PositionWindowRect.right-WindowRect.left,// Calculate Window WidthWindowRect.bottom-WindowRect.top,// Calculate Window HeightNULL,// No Parent WindowNULL,// No MenuhInstance,// InstanceNULL)))// Dont Pass Anything To WM_CREATE{KillGLWindow();// Reset The DisplayMessageBox(NULL,"Window Creation Error.","ERROR",MB_OK|MB_ICONEXCLAMATION);return FALSE;// Return FALSE}staticPIXELFORMATDESCRIPTOR pfd=// pfd Tells Windows How We Want Things To Be{sizeof(PIXELFORMATDESCRIPTOR),// Size Of This Pixel Format Descriptor1,// Version NumberPFD_DRAW_TO_WINDOW |// Format Must Support WindowPFD_SUPPORT_OPENGL |// Format Must Support OpenGLPFD_DOUBLEBUFFER,// Must Support Double BufferingPFD_TYPE_RGBA,// Request An RGBA Formatbits,// Select Our Color Depth0, 0, 0, 0, 0, 0,// Color Bits Ignored0,// No Alpha Buffer0,// Shift Bit Ignored0,// No Accumulation Buffer0, 0, 0, 0,// Accumulation Bits Ignored16,// 16Bit Z-Buffer (Depth Buffer)  0,// No Stencil Buffer0,// No Auxiliary BufferPFD_MAIN_PLANE,// Main Drawing Layer0,// Reserved0, 0, 0// Layer Masks Ignored}; if (!(hDC=GetDC(hWnd)))// Did We Get A Device Context?{KillGLWindow();// Reset The DisplayMessageBox(NULL,"Can''t Create A GL Device Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);return FALSE;// Return FALSE}if (!(PixelFormat=ChoosePixelFormat(hDC,&pfd)))// Did Windows Find A Matching Pixel Format?{KillGLWindow();// Reset The DisplayMessageBox(NULL,"Can''t Find A Suitable PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);return FALSE;// Return FALSE}if(!SetPixelFormat(hDC,PixelFormat,&pfd))// Are We Able To Set The Pixel Format?{KillGLWindow();// Reset The DisplayMessageBox(NULL,"Can''t Set The PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);return FALSE;// Return FALSE}if (!(hRC=wglCreateContext(hDC)))// Are We Able To Get A Rendering Context?{KillGLWindow();// Reset The DisplayMessageBox(NULL,"Can''t Create A GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);return FALSE;// Return FALSE}if(!wglMakeCurrent(hDC,hRC))// Try To Activate The Rendering Context{KillGLWindow();// Reset The DisplayMessageBox(NULL,"Can''t Activate The GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);return FALSE;// Return FALSE}ShowWindow(hWnd,SW_SHOW);// Show The WindowSetForegroundWindow(hWnd);// Slightly Higher PrioritySetFocus(hWnd);// Sets Keyboard Focus To The WindowReSizeGLScene(width, height);// Set Up Our Perspective GL Screenif (!InitGL())// Initialize Our Newly Created GL Window{KillGLWindow();// Reset The DisplayMessageBox(NULL,"Initialization Failed.","ERROR",MB_OK|MB_ICONEXCLAMATION);return FALSE;// Return FALSE}return TRUE;// Success}LRESULT CALLBACK WndProc(HWNDhWnd,// Handle For This WindowUINTuMsg,// Message For This WindowWPARAMwParam,// Additional Message InformationLPARAMlParam)// Additional Message Information{switch (uMsg)// Check For Windows Messages{case WM_ACTIVATE:// Watch For Window Activate Message{if (!HIWORD(wParam))// Check Minimization State{active=TRUE;// Program Is Active}else{active=FALSE;// Program Is No Longer Active}return 0;// Return To The Message Loop}case WM_SYSCOMMAND:// Intercept System Commands{switch (wParam)// Check System Calls{case SC_SCREENSAVE:// Screensaver Trying To Start?case SC_MONITORPOWER:// Monitor Trying To Enter Powersave?return 0;// Prevent From Happening}break;// Exit}case WM_CLOSE:// Did We Receive A Close Message?{PostQuitMessage(0);// Send A Quit Messagereturn 0;// Jump Back}case WM_KEYDOWN:// Is A Key Being Held Down?{keys[wParam] = TRUE;// If So, Mark It As TRUEreturn 0;// Jump Back}case WM_KEYUP:// Has A Key Been Released?{keys[wParam] = FALSE;// If So, Mark It As FALSEreturn 0;// Jump Back}case WM_SIZE:// Resize The OpenGL Window{ReSizeGLScene(LOWORD(lParam),HIWORD(lParam));  // LoWord=Width, HiWord=Heightreturn 0;// Jump Back}}// Pass All Unhandled Messages To DefWindowProcreturn DefWindowProc(hWnd,uMsg,wParam,lParam);}int WINAPI WinMain(HINSTANCEhInstance,// InstanceHINSTANCEhPrevInstance,// Previous InstanceLPSTRlpCmdLine,// Command Line ParametersintnCmdShow)// Window Show State{MSGmsg;// Windows Message StructureBOOLdone=FALSE;// Bool Variable To Exit Loop// Ask The User Which Screen Mode They Preferif (MessageBox(NULL,"Would You Like To Run In Fullscreen Mode?", "Start FullScreen?",MB_YESNO|MB_ICONQUESTION)==IDNO){fullscreen=FALSE;// Windowed Mode}// Create Our OpenGL Windowif (!CreateGLWindow("Lionel Brits & NeHe''s 3D World Tutorial",640,480,16,fullscreen)){return 0;// Quit If Window Was Not Created}while(!done)// Loop That Runs While done=FALSE{if (PeekMessage(&msg,NULL,0,0,PM_REMOVE))// Is There A Message Waiting?{if (msg.message==WM_QUIT)// Have We Received A Quit Message?{done=TRUE;// If So done=TRUE}else// If Not, Deal With Window Messages{TranslateMessage(&msg;// Translate The MessageDispatchMessage(&msg;// Dispatch The Message}}else// If There Are No Messages{// Draw The Scene.  Watch For ESC Key And Quit Messages From DrawGLScene()if ((active && !DrawGLScene()) || keys[VK_ESCAPE])// Active?  Was There A Quit Received?{done=TRUE;// ESC or DrawGLScene Signalled A Quit}else// Not Time To Quit, Update Screen{SwapBuffers(hDC);// Swap Buffers (Double Buffering)if (keys[''B''] && !bp){bp=TRUE;blend=!blend;if (!blend){glDisable(GL_BLEND);glEnable(GL_DEPTH_TEST);}else{glEnable(GL_BLEND);glDisable(GL_DEPTH_TEST);}}if (!keys[''B'']){bp=FALSE;}if (keys[''F''] && !fp){fp=TRUE;filter+=1;if (filter>2){filter=0;}}if (!keys[''F'']){fp=FALSE;}if (keys[VK_PRIOR]){z-=0.02f;}if (keys[VK_NEXT]){z+=0.02f;}if (keys[VK_UP]){xpos -= (float)sin(heading*piover180) * 0.05f;zpos -= (float)cos(heading*piover180) * 0.05f;if (walkbiasangle >= 359.0f){walkbiasangle = 0.0f;}else{walkbiasangle+= 10;}walkbias = (float)sin(walkbiasangle * piover180)/20.0f;}if (keys[VK_DOWN]){xpos += (float)sin(heading*piover180) * 0.05f;zpos += (float)cos(heading*piover180) * 0.05f;if (walkbiasangle <= 1.0f){walkbiasangle = 359.0f;}else{walkbiasangle-= 10;}walkbias = (float)sin(walkbiasangle * piover180)/20.0f;}if (keys[VK_RIGHT]){heading -= 1.0f;yrot = heading;}if (keys[VK_LEFT]){heading += 1.0f;yrot = heading;}if (keys[VK_PRIOR]){lookupdown-= 1.0f;}if (keys[VK_NEXT]){lookupdown+= 1.0f;}if (keys[VK_F1])// Is F1 Being Pressed?{keys[VK_F1]=FALSE;// If So Make Key FALSEKillGLWindow();// Kill Our Current Windowfullscreen=!fullscreen;// Toggle Fullscreen / Windowed Mode// Recreate Our OpenGL Windowif (!CreateGLWindow("Lionel Brits & NeHe''s 3D World Tutorial",640,480,16,fullscreen)){return 0;// Quit If Window Was Not Created}}}}}// ShutdownKillGLWindow();// Kill The Windowreturn (msg.wParam);// Exit The Program} ;  What code did you add to try to alter the illumination?In future, when posting large amounts of code, please use [source] tags.Enigma 