Noob question: Draw a quad parallel to the view

ok what I want to do is to draw a quad in the scene that lays on a plane parallel to the view. So it should appear flat.

More in particular, I think I didn't get very well how the mechanism of gluLookAt works in comparison with the functions glTranslate and glRotate:

If I position the view "manually" usi开发者_StackOverflow中文版ng the functions glTranslate and glRotate whenever I draw an object its position is relative to the current view. And I understand that this is due to the transformation matrix in the stack.

However, when I use the gluLookAt (that should automatically set the view), the coordinates of the object I want to draw must be "absolute" to be shown properly.

Thanks in advance.

This tutorial describes how to do billboarding in OpenGL.