After quite a bit of tinkering, I finally got an accurate depth image rendered to my FBO/into a texture. However, I can't seem to get the actual shadows to cast. I'm using http://fabiensanglard.net/shadowmapping/index.php as a reference.

[attachment=12969:depth_shadow.png]

This is my depth map as drawn from the lights POV, as per gDebugger after adjusting the slider to represent roughly .50 out of 1.0. Here is how my scene looks after rendering.

[attachment=12970:scene.png]

I've got my matrices, shaders, etc. setup exactly as presented in Fabien Sanglards tutorial. I'm not necessarily looking for answer, but rather a point in to what would be causing my entire scene to be gray, rather than have shadows applied.

The only thing I can think of is how I have my perspective established:

       //set pers settings
       this->r_cam->perspective(CAMERA_FOVX,
       (800.0f) / (600.0f),10.0f,40000.0f);
       //load pers into matrix
	glLoadMatrixf(&this->r_cam->getProjectionMatrix()[0][0]);

Perhaps my zNear(10.0f) is too small? Or perhaps zFar(40000.0f) is too large? The depthmap shown in gDebugger looks alright to me, though. I'm using VBOs and AssImp if that affects anything; I can post my final scene rendering code(or any requested portion ) if that would aid in determining what's going on; I didn't want to clutter my first post too much Thank you!

[quote name='Nyssa' timestamp='1356515907' post='5014371']
same position as the camera
[/quote]

Wouldn't that mean that the shadows would never be visible? Since all shadowed parts are behind the objects that cast the shadows.

Actually, I think I had the camera opposite of the light when I took the shot; the giant gray mass stays as a giant gray mass though, no matter where i put my camera :P

Still haven't managed to fix it, but that is defintely one of the better explanations I've come across for the technique! I understand the idea a LOT better.

So, here's a giant wall of code!

While I'm thinking about it, I'm using SDL, GLEW, AssImp, and Bullet. I currently have Bullet disabled while I work on the shiny graphics junk.

static double modelView[16];    
static double projection[16];    
static float tex[16];        
// This is matrix transform every coordinate x,y,z    
// x = x* 0.5 + 0.5    
// y = y* 0.5 + 0.5    
// z = z* 0.5 + 0.5    
// Moving from unit cube [-1,1] to [0,1]      
const GLdouble bias[16] = {            
0.5, 0.0, 0.0, 0.0,        
0.0, 0.5, 0.0, 0.0,        
0.0, 0.0, 0.5, 0.0,    
0.5, 0.5, 0.5, 1.0};        

// Grab modelview and transformation matrices    
glGetDoublev(GL_MODELVIEW_MATRIX, modelView);    
glGetDoublev(GL_PROJECTION_MATRIX, projection);        

glActiveTexture(GL_TEXTURE7);    
glMatrixMode(GL_TEXTURE);      

glLoadMatrixd(bias);    
// concatating all matrice into one.    
glMultMatrixd (projection);    
glMultMatrixd (modelView);    
// Go back to normal matrix mode    
glMatrixMode(GL_MODELVIEW);

I swapped the glActiveTexture before the glMatrixMode() call so that the data is actually writing to the appropriate texture matrix unit. Otherwise, in terms of FBO and depthmap generation are entirely identical to what's in the tutorial. I suspect after a whole bunch of goofing around that my issues lie in the values getting pushed to the texture matrix.

if(mode == R_NORM || mode == R_DEBUG)
{
    glEnable(GL_COLOR_MATERIAL);
    glEnable(GL_TEXTURE_2D);
    glEnableClientState(GL_TEXTURE_COORD_ARRAY);
    glEnableClientState(GL_NORMAL_ARRAY);
    glEnableClientState(GL_VERTEX_ARRAY);
    glBindBuffer(GL_ARRAY_BUFFER,model.t_buff);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,model.i_buff);

    glTexCoordPointer(2, GL_FLOAT,sizeof(vert),BUFFER_OFFSET(0));
    glNormalPointer(GL_FLOAT,sizeof(vert),BUFFER_OFFSET(sizeof(GLfloat)*2));
    glVertexPointer(3, GL_FLOAT,sizeof(vert),BUFFER_OFFSET(sizeof(GLfloat)*5));
    glClientActiveTexture(GL_TEXTURE0+ model.mats.at(0).texid);

    c_render.use_program(model.shaderid);
    int sdw_loc = glGetUniformLocation(model.shaderid,"ShadowMap");
    glUniform1i(sdw_loc,c_render.depth_tex);

    glActiveTexture(GL_TEXTURE0 + model.mats.at(0).texid);
    glBindTexture(GL_TEXTURE_2D, model.mats.at(0).texid);

    glActiveTexture(GL_TEXTURE7);
    glBindTexture(GL_TEXTURE_2D,c_render.depth_tex);

    glDrawElements(GL_TRIANGLES,(model.f_index.size()*3),GL_UNSIGNED_INT,0);

    glBindBuffer(GL_ARRAY_BUFFER, 0);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
    glActiveTexture(GL_TEXTURE0);
    glClientActiveTexture(GL_TEXTURE0);
    glDisableClientState(GL_VERTEX_ARRAY);
    glDisableClientState(GL_TEXTURE_COORD_ARRAY);
    glDisableClientState(GL_NORMAL_ARRAY);
    c_render.use_program(0);
    glBindTexture(GL_TEXTURE_2D,0);
    glDisable(GL_TEXTURE_2D);
}
else
if(mode == R_DEPTH)
{
    glEnableClientState(GL_NORMAL_ARRAY);
    glEnableClientState(GL_VERTEX_ARRAY);
    glBindBuffer(GL_ARRAY_BUFFER,model.t_buff);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,model.i_buff);

    glNormalPointer(GL_FLOAT,sizeof(vert),BUFFER_OFFSET(sizeof(GLfloat)*2));
    glVertexPointer(3, GL_FLOAT,sizeof(vert),BUFFER_OFFSET(sizeof(GLfloat)*5));            
    glDrawElements(GL_TRIANGLES,(model.f_index.size())*3,GL_UNSIGNED_INT,0);
    glBindBuffer(GL_ARRAY_BUFFER, 0);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
    glDisableClientState(GL_VERTEX_ARRAY);
    glDisableClientState(GL_NORMAL_ARRAY);
}

Is my rendering code(cut some of the extra crap out for readibility.) I use the section under R_DEPTH to generate the depth map, which is valid from what I can tell, and then R_NORM/R_DEBUG is what renders the scene.

What leads me to think that perhaps it's a texture matrix issue is that gDebugger spits out values that aren't even remotely clamped to 0,1 - which is what I assume they are supposed to be. He didn't mention in the tutorial but I suppose then that if your scene is of a decent scale/shadow map is of a larger resolution that you have to normalize the light proj/view matrix values?

Also, for clarification: the depth map looks like it should from the lights point of view. My texture is indeed initiated with both MIN/MAG filter settings. The one thing that raised a concern for me is that the tutorial code doesn't actually compile and run properly for me; the binary works quite fine but when I tried compiling his code and running it it didn't even create a FBO.

Had a big post about using the inverse modelview but it doesn't actually appear to affect my output.

EDIT: After some goofing, I removed anything that would screw with my texture matrix(including disabling texture coord pointers/arrays.) I would say that my values for the matrix make sense now, but all in all it still doesn't work. I have a proper depth map, valid fbo, and I'm assuming to be decent values for my texture matrix. I'm really at a loss as to why it wouldn't be working, perhaps besides drivers or something silly that I'm overlooking.

EDIT2: Got it! For some reason I was sending the texture ID, not the texture UNIT to the shader. :S

[attachment=13233:butts2.png]