hi all, i'm rendering my scene and then using glCopyTexSubImage to read back the framebuffer's depth info into a texture i created (with format DEPTH_COMPONENT) it dosn't seem to be working, its just all white... i've searched google with not much luck. its my understanding that the depth value should be clamped to 0-1, this is correct? any help would be greatly appreciated Cheers -Danu my code:

// init code
glGenTextures(1, &this->apiName );
glBindTexture( GL_TEXTURE_2D, this->apiName );
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
glTexImage2D( GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, width, height, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, NULL );

// rendering code
device->flush();

// copy zbuffer into the depth texture
glBindTexture(GL_TEXTURE_2D, this->apiName);
glCopyTexSubImage2D( GL_TEXTURE_2D, 0, 0, 0, 0, 0, this->width, this->height);

// also tried this, but no cigar:
// glCopyTexImage2D( GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, 0, 0, this->width, this->height, 0);

Quote:Original post by zedzeek
thats cause the depth values are most likely in the range 0.998 -> 1.0 thus appear white
u can verfy this by constraining the znear - far values
eg change gluPerspective( 60,1, 0.1, 200 ) to gluPerspective( 60,1, 50, 200 );

another way is to render with linear fog, 0.0 == near 1.0 == far

Quote:Original post by silvermace
is this range of 0.998 -> 1.0 any use to me? i mean can it be used succesfully say in a depth of field shader?

if not, is there any way i could change this to be more usfull?

Quote:any info on how to re-map to a more linear scale so that i can visualise it through a grayscale image?

Quote:Original post by zedzeek
i dont know about vastly exagetrated, perhaps slight though

say u have a near = 0.1 and far at 1000.0