One simple question:
How to make a mirror in room?

orthogonal mirror is very simple
say you want mirror parallel to XY plane, that’s one of general 2 solutions I know (without stencil buffer):

  1. draw everything with inversed Z coordinate, thus if your whole mirror has all Z coordinates = some_z you need to replace z coordinate of your objects with
    (-z + 2*some_z)
  2. clean z-buffer
  3. draw alpha-blended poly over the mirror
  4. draw everything

hope it helps

Go to http://nehe.gamedev.net/
There is a very good tutorial about mirrors (Using the stencil buffer).


viewport also is a solution method