calculate zBuffer-accept wrong values
calculate zBuffer-accept wrong values
I am trying to calculate my zBuffer and I accept wrong values. the model that I am loading has to have diffrent Zbuffer values but I dont accept them my values are defined ZNEAR 1.0f ZFAR 1500.0f my code is:
//calculate the zBuffer
GLfloat get_gl_depth()
{
Pipeline p;
int w = glutGet( GLUT_WINDOW_WIDTH );
int h = glutGet( GLUT_WINDOW_HEIGHT );
glBindBuffer( GL_PIXEL_PACK_BUFFER, pbo );
glBufferData( GL_PIXEL_PACK_BUFFER, w * h * sizeof( GLfloat ), 0, GL_STREAM_READ );
glReadPixels( 0, 0, w, h, GL_DEPTH_COMPONENT, GL_FLOAT, 0 );
GLfloat* ptr = (GLfloat*)glMapBuffer( GL_PIXEL_PACK_BUFFER, GL_READ_ONLY );
unsigned short* buffer=new unsigned short[w*h];
unsigned short* current = buffer;
if (ptr != nullptr)
{
for (int i=0;i<w*h;i++)
{
GLfloat distance =ZNEAR+(GLfloat(ptr[i])*(ZFAR-ZNEAR));
*current++ = unsigned short(distance + 0.5);
}
}
glUnmapBuffer( GL_PIXEL_PACK_BUFFER );
glBindBuffer( GL_PIXEL_PACK_BUFFER, 0 );
delete[] buffer;
return 0;
}
After that I am calling a func that loads all this:
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glEnable( GL_DEPTH_TEST );
glDepthMask(GL_TRUE);
const float lightZ = (sinf(m_scale) + 1.0f) / 2.0f;
PointLight pl[10];
int numLights = 0;
pl[numLights++] = CreateLight(0, 0, 0, 255.0f, 0.0f, 0.0f);
pl[numLights++] = CreateLight(0, 0, 100, 0.0f, 255.0f, 0.0f);
pl[numLights++] = CreateLight(100, 0, 100, 0.0f, 0.0f, 255.0f);
m_pEffect->SetPointLights(numLights, pl);
m_pEffect->SetPointLights(3, pl);
Pipeline p;
Vector3f cameraUp = CameraUpVector();
p.SetCamera(m_cameraPosition, m_cameraTarget, cameraUp);
p.SetPerspectiveProj(60.0f, WINDOW_WIDTH, WINDOW_HEIGHT, ZNEAR, ZFAR);
m_pEffect->SetWVP(p.GetWVPTrans());
m_pEffect->SetWorldMatrix(p.GetWorldTrans());
m_pEffect->SetDirectionalLight(m_directionalLight);
m_pEffect->SetEyeWorldPos(m_cameraPosition);
m_pEffect->SetMatSpecularIntensity(0.0f);
m_pEffect->SetMatSpecularPower(0);
m_pMesh->Render();
get_gl_depth(/*WINDOW_WIDTH, WINDOW_HEIGHT*/);
glutSwapBuffers();
This is the func that initlize the first values:
Vector3f Pos(0.0f, 0.0f, -700.0f);
Vector3f Target(0.0f, 0.0f, 0.00001f);
Vector3f Up(0.0, 1.0f, 0.0f);
m_cameraPosition = Pos;
m_cameraTarget = Target;
Please help me … I tried to understand what is wrong in my calculation but didnt understand
maybe the projection is not right?
or the ZFAR and ZNEAR
??
I changed it to:
#define ZNEAR 400.0f
#define ZFAR 700.0f
and I am calculating the zbuffer and this is not equal to what I accept