Hi,
can somebody point me out why, or even better in which cases, glReadPixels doesn’t find the right depth coordinates?
I’m using
glReadPixels(oldX - winX, oldY - winY, 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &pixel);
The problem is as soon as I have rotated the model only slightly I get an error of at least 10% (depth not found, so pixel is something close to zero (5.1e-308)).
That’s my Draw-func, in case it is needed.
GLvoid __fastcall View: raw(bool trans)
{
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_LIGHT1);glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
glTranslated(GLTranslateX, 0.0, 0.0);
glTranslated(0.0, GLTranslateY, 0.0);
glTranslated(0.0, 0.0, GLTranslateZ );glPushMatrix();
glRotated(GLRotateX,1.0,0.0,0.0);
glRotated(GLRotateY,0.0,1.0,0.0);glGetDoublev(GL_MODELVIEW_MATRIX, mvMatrix);
if(ObjList)
{
glEnable(GL_DEPTH_TEST);
glMaterialfv(GL_FRONT_AND_BACK,GL_AMBIENT_AND_DIFFUSE,mat_ambient);ObjList->Draw(GL_TRIANGLE_STRIP); glMaterialfv(GL_FRONT_AND_BACK,GL_AMBIENT_AND_DIFFUSE,mat_ones);}
glDisable(GL_LIGHT1);
glDisable(GL_LIGHT0);
glDisable(GL_LIGHTING);glPopMatrix();//Transform
glPopMatrix();//Rotate
}
Further I would like to know how to deal with the glPolygonOffset. I tried couple things, yes I searched the forum and I read the snippet in the Red Book, but it didn’t really help me.
I’m trying to draw a patch on top of an object. The coords for the patch are retrieved with the function above and gluUnproject.
Thanks,
Martin
[This message has been edited by mphanke (edited 06-03-2002).]