hey dude first thing is your perspective calculation (the z near z far problem!)



void T3DPlanet::GetOGLPos(int x, int y, t3dpoint & np, t3dpoint & fp)
{
glGetDoublev( GL_MODELVIEW_MATRIX, modelview );
// glGetDoublev( GL_PROJECTION_MATRIX, projection );
glMatrixMode(GL_PROJECTION); // Change Matrix Mode to Projection
glPushMatrix();
glLoadIdentity(); // Reset View
gluPerspectiveA(90.0f, DISPLAY_WIDTH/DISPLAY_HEIGHT,1000.0f, 2000.0f); // Do the perspective calculations. Last value = max clipping depth
glGetDoublev( GL_PROJECTION_MATRIX, projection );
glPopMatrix();
glMatrixMode(GL_MODELVIEW);

// int i;
// for (i=0; i<16;i++) ShowMessage(FloatToStr(projection));
glGetIntegerv( GL_VIEWPORT, viewport );
double nx,ny,nz; double fx,fy,fz;
float winX = float(x);
float winY = float(viewport[3]) - float(y);
t3dpoint neara;
t3dpoint fara;
gluUnProject(winX, winY, 0, modelview, projection, viewport, &nx, &ny, &nz);
gluUnProject(winX, winY, 1, modelview, projection, viewport, &fx, &fy, &fz);
np.x = nx;
np.y = ny;
np.z = nz;
NEAR_HIT = np;
fp.x = fx;// - nx;
fp.y = fy;// - ny;
fp.z = fz;// - nz;
FAR_HIT = fp;
}

and heres a thing that i use when mouse cursor is moving through window and it uses the proc above


[code]
void __fastcall T3DPlanet::MouseInsertMove(int X, int Y,HWND hwnd)
{

glViewport(0, 0, int( DISPLAY_WIDTH), int(DISPLAY_HEIGHT)); // Set the viewport for the OpenGL window
glMatrixMode(GL_PROJECTION); // Change Matrix Mode to Projection
glLoadIdentity(); // Reset View
gluPerspectiveA(90.0, DISPLAY_WIDTH/DISPLAY_HEIGHT,1000.0f, 1000.0 * 1000.0 * 1000.0 * 1000.0); // Do the perspective calculations. Last value = max clipping depth
glMatrixMode(GL_MODELVIEW);

sx = X;
sy = Y;
//glClear(GL_COLOR_BUFFER_BIT);
//glClear(GL_DEPTH_BUFFER_BIT);
glPushMatrix();
glLoadIdentity();
gluLookAt(EYEPOS.x,EYEPOS.y,EYEPOS.z,EYEPOS.x+EYELOOKATPOINT.x,
EYEPOS.y-EYELOOKATPOINT.y,EYEPOS.z-EYELOOKATPOINT.z,
0,1,0);
if (insert_mode == true) {
TPoint mouse;
GetCursorPos(&mouse); // Gets The Current Cursor Coordinates (Mouse Coordinates)
ScreenToClient(hwnd, &mouse);
t3dpoint np, fp;
GetOGLPos(mouse.x,mouse.y,np,fp);
t3dpoint vLine[2];
np = vectorAB(NEAR_HIT,FAR_HIT);
np = Normalize( np ); //nice one milion kilometers away ;u
np = vector_multiple(np, 1000.0f * 1000.0f * 1000.0f);
vLine[0] = NEAR_HIT;
vLine[1] = vectors_add(NEAR_HIT, np);
//
//
int i;
for (i=0; i<SCENE_SELECTION[0].selectedfaces.Length;i++)
if (LineIntersectFaceFromModel(SCENE_SELECTION[0].selectedfaces,PLANET_MODEL,vLine, HIT_SPACE_POSITION ) == true)
return;
}
glPopMatrix();
}
[/code]



Ah please dont ask me why i call perspective projection and loadidentity before getoglpos ( i cant remember!!!)
well i remember that just draw your scene then use getoglpos


but it returns me two POINTS (NOT THE DEPTH POINT or etc) just 2 points that make the line from screen to the outter space ;x
then i must find a collision point between polygon ray intersection


I think you can bypass ray poly intersection by reading the acutal depth value from image (by glReadPixels let assume that will be a var called KKK)

so then gluUnProject(winX, winY, KKK, modelview, projection, viewport, &nx, &ny, &nz); nx ny nz are output pos vals but i don't know if it works

===================

and here's a proove that it works :X but watch after 1 min :/

[media][/media]

the func void T3DPlanet::GetOGLPos(int x, int y, t3dpoint & np, t3dpoint & fp)

void gluPerspectiveA(GLfloat fovy, GLfloat aspect, GLfloat zmin, GLfloat zmax)
{
GLfloat xmin, xmax, ymin, ymax;
ymax = zmin * tan(fovy * M_PI / 360.0);
ymin = -ymax;
xmin = ymin * aspect;
xmax = ymax * aspect;
glFrustum(xmin, xmax, ymin, ymax, zmin, zmax);
}



provides the correct X and Y values for mouse cursor,

The idea of my soulition is: (i will explain the code now)
the idea is as follows:
set z near and z far closely
gluPerspectiveA(90.0f, DISPLAY_WIDTH/DISPLAY_HEIGHT,1000.0f, 2000.0f);
set the camera

then check nearest depth val and the farthest, then make from them a line and test whatever you want

gluUnProject(winX, winY, 0, modelview, projection, viewport, &nx, &ny, &nz); //the point on your screeen! (depth value 0,0f)
gluUnProject(winX, winY, 1, modelview, projection, viewport, &fx, &fy, &fz); //pushed far away point (depth value 1.0f)

Maybye you are not familiar with the dpeth values they are from 0 to 1 (depending on znear/zfar value 0.75 from depth vcan be farther than 0.75 from diffferent znear/zfar perspective ble ble ble ble )


void T3DPlanet::GetOGLPos(int x, int y[..])
{
[...]
glGetIntegerv( GL_VIEWPORT, viewport );
float winX = float(x);
float winY = float(viewport[3]) - float(y);

//optional readpixels

//optional one gluunproject(winx,winy, readpixeldepth, modelview, projection, viewport, outputx,outputy,outputz);








if you do not want to make rays and then test some shit you use)
if you use glReadPixels() with the same x,y values (winX, winY) range 1 GL_DEPTH_COMPONENT (or GL_DEPTH_COMPONENT24)

after reading the depth value from the pixel you
call glunproject
heres is a pixel reading

void __fastcall READ_RGBA_FROM_OGL_WINDOW(int x,int height, int y, int & r, int & g, int & b, int & a)
{


unsigned char* pdata = new unsigned char[4];
glReadBuffer(GL_COLOR_BUFFER_BIT);

glReadPixels(x,height-y,1,1,GL_RGBA,GL_UNSIGNED_BYTE,pdata);

r = pdata[0];
g = pdata[1];
b = pdata[2];
a = pdata[3];
// delete B2;
delete [] pdata;
}

//so for depth is should be but i dont know if that is correct

float __fastcall READ_DEPTH_FROM_OGL_WINDOW(int x,int height, int y)
{

unsigned char* pdata = new unsigned char[1];
glReadBuffer(GL_DEPTH_BUFFER_BIT);
glReadPixels(x,height-y,1,1,GL_DEPTH_COMPONENT,GL_UNSIGNED_BYTE,pdata);

return float(pdata[0]) / 255.0f;

}



[color=#ff0000]I have tried everything but not getting the exact X and Y values. - no you didin't
[color=#ff0000]I am applying glPerspective() in real-time (display function) thats why
- I don;t understand, you display the scene and you store for it a modelview matrix, projection matrix , and viewport
so you can call fcking gluUnProject

and do not use so big ratio between z_near/z_far


[color=#ff0000]I think I have to apply it with a specific matrix but i dont know which matrix. - ah HELL NO !!!

[color=#ff0000]I do not want to select vertex or something like that I just need 3D coordinates at the click position.


So WHA THE HELL ARE YOU WAITING FOR?
CLEAN YOUR CODE


and do as follows


draw the scene

store modelview matrix and stroe viewport also
(when want to click)
change perspective to 'nicest z_near/z_far aspect ratio)
store projection matrix
call gluUnProject and get the values

be happy ;(


I still have no idea what are you doing wrong dude

i am having trouble with reading from depth buffer (reading the winZ) if i solve this i will post it, i think tommorow

Lol i have compiled your code and did the same with this double (changed to float) but still cant read the winZ lol ; ]
remember to read pixels only when you have depth buffer filled with this what you want to check, do ont call getoglpos whenever you want because t might not work