   Opengl layers?
  Is it possible to make different layers in openGL? because i have an 3d-scene, and i want to create an 2d-layer in front of it, so i can make things like buttons and text fields in front of the scene. Is there anyone who knows how to do this?Greetz, Leon   
glMatrixMode(GL_PROJECTION);glLoadIdentity();glOrtho(0.0, windowwidth, 0.0, windowheight, -1.0, 1.0);glMatrixMode(GL_MODELVIEW);glDisable(GL_DEPTH_TEST);glDepthMask(GL_FALSE);You can tweak the values for glOrtho to your liking.   ;  You mean something like:glMatrixMode(GL_PROJECTION);glLoadIdentity();gluPerspective(45.0f, (GLfloat)1920/(GLfloat)1200, 0.1f, 2000.0f);glMatrixMode(GL_MODELVIEW);glBegin(GL_QUADS);(3d gl objects)glEnd();glMatrixMode(GL_PROJECTION);glLoadIdentity();glOrtho(0.0, windowwidth, 0.0, windowheight, -1.0, 1.0);glMatrixMode(GL_MODELVIEW);glDisable(GL_DEPTH_TEST);glDepthMask(GL_FALSE);glBegin(GL_QUADS);(2d gl objects)glEnd();?;  That's the usual way of doing it (although you don't have to draw all your objects in a glBegin/End call). Also remember you need to reenable the depth test and depth writing at the start of the next frame otherwise the state will carry over.   