Hi, I am trying to fog 3d geometry to a fullscreen texture.

So far I have my fog shader and can fog to the image but am stuck on how to generate correct UV coords for the fullscreen fog texture so that it maps exactly to the correct pixel on the 3D object.

Do you think I am following the best route to create this effect or are there other ways?

Using alpha to show through the texture image underneath seems problematic since I need to render multiple objects, some with transparency.

Should I perhaps instead render the scene to a colour and depth buffer and just merge the two textures on the basis of their depth?