Making The Polygon "really" have two sides for games?

I am developing this game engine in OpenGL and I am working on some game models for it and it seems I can’t get the model to as well get render the inside.

I planed on using this for model trees and what not that can see the other side of.
I was thinking on creating two faces to gather to that face different directions then each other, but I thought their would be a more professional way.

Thanks, Ajm113.

I think there’s a Two Sided button that does what you want. Otherwise, Shift D, rotate 180 degrees, and offset just a tiny bit.

Yeah I tried that button, but it seems not to have effect, any other ideas?

If it is only possible with duplicating faces then I guest thats they way.

To get the twosided button to work you need to select one face in uv-face mode, then hit twoside, then select all of the faces (a) and then hit copy-draw-mode. If you go to textured mode (d, textured) then you will be able to look around and check.