OpenGL-渲染3D纹理

Question

Idea: I have been trying to develop code which can take several (ten) slices of 2D images and render them as a 3D texture. I have so far used glTexImage3D and glTexSubImage3D upon suggestions from my previous post here: OpenGL - 'glTexSubImage3D': identifier not found

I have been based my work off of NeHe's texture mapping tutorial here: http://nehe.gamedev.net/tutorial/lesson_06_texturing_update/47002/

The flow of function calls in the NeHe's tutorial in main() proceeds like this: CreateGLWindow() , InitGL() , LoadGLTextures() , DrawGLScene() . I have only made changes to the code commencing upwards from DrawGLScene() while, everything below that function is the same as in my code.

Problem: Everything in the code seemingly looks right but, there is nothing being rendered on the screen. I have spent two days on this trying to get it to work to no avail. What am I missing? Is there something that I am doing incorrectly?

EDITED CODE

#include "windows.h"        
#include "stdio.h"          
#include "gl\gl.h"          
#include "gl\glu.h"         
#include "GLext.h"
#include "SOIL.h"

HDC          hDC=NULL;      
HGLRC        hRC=NULL;      
HWND         hWnd=NULL;     
HINSTANCE    hInstance;     

bool    keys[256];          
bool    active=TRUE;        
bool    fullscreen=TRUE;    

GLfloat xrot;               
GLfloat yrot;               
GLfloat zrot;               

GLuint  m_nTexId;           
unsigned char tex;

int h = 1024;           
int w = 256;
int slices = 10;

GLfloat dOrthoSize = 1.0f;

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);   

// EDIT HERE

PFNGLTEXIMAGE3DPROC TexImage3D;
PFNGLTEXSUBIMAGE3DPROC TexSubImage3D;
PFNGLCOPYTEXSUBIMAGE3DPROC CopyTexSubImage3D;

int LoadGLTextures()    
{
    glGenTextures(1,(GLuint*)&m_nTexId );

    if(m_nTexId == 0)
    return false;

    glBindTexture( GL_TEXTURE_3D, m_nTexId );
    glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_BORDER);
    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    return true;
}


GLvoid ReSizeGLScene(GLsizei width, GLsizei height)     
{
    if (height==0)                                      
    {
        height=1;
    }

    glViewport(0,0,width,height);

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();

    gluPerspective(45.0f,(GLfloat)width/(GLfloat)height,0.1f,100.0f);

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();   
}

int InitGL(GLvoid)  
{
    if (!LoadGLTextures())
    {
        return FALSE;
    }

    glEnable(GL_TEXTURE_3D);
    glShadeModel(GL_SMOOTH);
    glClearColor(0.0f, 0.0f, 0.0f, 0.5f);   
    glClearDepth(1.0f);
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LEQUAL); 
    glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);

// EDIT HERE

    TexImage3D = (PFNGLTEXIMAGE3DPROC) wglGetProcAddress("glTexImage3D");
    TexSubImage3D = (PFNGLTEXSUBIMAGE3DPROC) wglGetProcAddress("glTexSubImage3D");
    CopyTexSubImage3D = (PFNGLCOPYTEXSUBIMAGE3DPROC) wglGetProcAddress("glCopyTexSubImage3D");

    return TRUE;
}

#define MAP_3DTEXT( TexIndex ) \
    glTexCoord3f(0.0f, 0.0f, ((float)TexIndex+1.0f)/2.0f);  \
    glVertex3f(-dOrthoSize,-dOrthoSize,TexIndex);\
    glTexCoord3f(1.0f, 0.0f, ((float)TexIndex+1.0f)/2.0f);  \
    glVertex3f(dOrthoSize,-dOrthoSize,TexIndex);\
    glTexCoord3f(1.0f, 1.0f, ((float)TexIndex+1.0f)/2.0f);  \
    glVertex3f(dOrthoSize,dOrthoSize,TexIndex);\
    glTexCoord3f(0.0f, 1.0f, ((float)TexIndex+1.0f)/2.0f);  \
    glVertex3f(-dOrthoSize,dOrthoSize,TexIndex);


int DrawGLScene(GLvoid)
{
    PFNGLTEXIMAGE3DPROC glTexImage3D = (PFNGLTEXIMAGE3DPROC) wglGetProcAddress("glTexImage3D");
    PFNGLTEXSUBIMAGE3DPROC glTexSubImage3D = (PFNGLTEXSUBIMAGE3DPROC) wglGetProcAddress("glTexSubImage3D");
    PFNGLCOPYTEXSUBIMAGE3DPROC glCopyTexSubImage3D = (PFNGLCOPYTEXSUBIMAGE3DPROC) wglGetProcAddress("glCopyTexSubImage3D");

    glClear( GL_COLOR_BUFFER_BIT  | GL_DEPTH_BUFFER_BIT );

    //glEnable( GL_ALPHA_TEST );
    //glAlphaFunc( GL_GREATER, 0.2f );

    //glEnable(GL_BLEND);
    //glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );

    glMatrixMode( GL_MODELVIEW );
    glLoadIdentity();
    gluLookAt(0,0,-300,0,0,1,0,1,0);


    glEnable(GL_TEXTURE_3D);
    glBindTexture( GL_TEXTURE_3D,  m_nTexId );

    TexImage3D(GL_TEXTURE_3D, 0, GL_RGBA, w, h , slices, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL );


    glTranslatef( 0.0f, 0.0f, 100.0f );


    glBegin(GL_QUADS);
    tex = (unsigned char)SOIL_load_image("Data/PA_170090.png", &w, &h, NULL, 0);
    TexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 1, w, h, 1, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) tex);
    MAP_3DTEXT( 0.0f );
    glEnd();

    glBegin(GL_QUADS);
    tex = (unsigned char) SOIL_load_image("Data/PA_170091.png", &w, &h, NULL, 0);
    TexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 2, w, h, 1, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) tex);
    MAP_3DTEXT( 0.1f );
    glEnd();

    glBegin(GL_QUADS);
    tex = (unsigned char)SOIL_load_image("Data/PA_170092.png", &w, &h, NULL, 0);
    TexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 3, w, h, 1, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) tex);
    MAP_3DTEXT( 0.2f );
    glEnd();

    glBegin(GL_QUADS);
    tex = (unsigned char)SOIL_load_image("Data/PA_170093.png", &w, &h, NULL, 0);
    TexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 4, w, h, 1, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) tex);
    MAP_3DTEXT( 0.3f );
    glEnd();

    glBegin(GL_QUADS);
    tex = (unsigned char)SOIL_load_image("Data/PA_170094.png", &w, &h, NULL, 0);
    TexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 5, w, h, 1, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) tex);
    MAP_3DTEXT( 0.4f );
    glEnd();

    glBegin(GL_QUADS);
    tex = (unsigned char)SOIL_load_image("Data/PA_170095.png", &w, &h, NULL, 0);
    TexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 6, w, h, 1, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) tex);
    MAP_3DTEXT( 0.5f );
    glEnd();

    glBegin(GL_QUADS);
    tex = (unsigned char) SOIL_load_image("Data/PA_170096.png", &w, &h, NULL, 0);
    TexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 7, w, h, 1, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) tex);
    MAP_3DTEXT( 0.6f );
    glEnd();

    glBegin(GL_QUADS);
    tex = (unsigned char) SOIL_load_image("Data/PA_170097.png", &w, &h, NULL, 0);
    TexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 8, w, h, 1, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) tex);
    MAP_3DTEXT( 0.7f );
    glEnd();

    glBegin(GL_QUADS);
    tex = (unsigned char) SOIL_load_image("Data/PA_170098.png", &w, &h, NULL, 0);
    TexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 9, w, h, 1, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) tex);
    MAP_3DTEXT( 0.8f );
    glEnd();

    glBegin(GL_QUADS);
    tex = (unsigned char) SOIL_load_image("Data/PA_170099.png", &w, &h, NULL, 0);
    TexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 10, w, h, 1, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) tex);
    MAP_3DTEXT( 0.9f );
    glEnd();

    return TRUE;

}

Answer 1

Look at the function call TexSubImage3D, the argument depth is always 1, and you are incrementing only zoffset. Please keep the zoffset 0 and provide the depth/layer values from 8th argument (depth).

TexSubImage3D( enum target, int level, int xoffset, int yoffset, int zoffset, sizei width, sizei height, sizei depth, enum format, enum type, const void *data );