   Diffrent layers of fog? (Done)
  In Gl games like quake 3 I have seen fog done in layers, not uniform all over the entire "level."  How exactlly would I go about doing that without shaders?Thanks for any input.[edited by - skow on February 8, 2004 2:53:22 PM][edited by - skow on February 9, 2004 2:50:02 PM]
  The way i did it is drawing several fog quads and moving the textures on them in different directions, this actually made pretty realistic and considerably fast fog (the framerate of 6.x is caused by the high detail heightmap!). A still: [edited by - Tree Penguin on February 8, 2004 2:09:37 PM];  You''re probably looking for so called height based fog. This is made possible with the GL_EXT_fog_coord extension. Luckily NeHe has a tutorial on this very thing : Just check out Lesson 41Good luck ;  That fog does look nice and I've seen it used in several games.  The only problem is when you go into the fog; I'm working on a FP game where you can go down into fog.  Using 2d textures won't look good once you enter the fog, unless there is somthing I'm not thinging about.EDIT: GL_EXT_fog_coord...hah that makes it too easy, thanks for the info.  I think I'll be using that comboed with sprite fog to give it some "noise."Thanks guys. [edited by - skow on February 8, 2004 2:17:11 PM];  That might be the case, i am not really sure about it. Of course extentions are always better to use (faster, and probably looking better in most cases) but this is easier and it did suit my project. ;  I certonly think that that style of fog does look better TP while viewing it from outside the fog, but like I said it has limitations as you enter. ;  Certainly, but i know for sure there are ways to get that quality anyway when entering it without drastic framerate lowerings. I will look into that some time. ;  Hmm well I just read up on the glFogCoordEXT, there is a problem with that method.  It colors the polygons dependent what you set the vertex fog level at.This makes a good effect to look into fog, but once you neter the area it''s not very convincing.  For example say a lower part of an area is in fog.  You go down there and look up.  The upper area is still perfectly clear.I''m hoping to find a method like GL_FOG where things become harder to see depending how far you are away from them, not their location. ;  Try fragment shaders (if they are supported on your card). ;  Yeah, I need to do this with out shaders.Here is a picture of the problem with fog_coords, looking out from in the fog. [edited by - skow on February 8, 2004 3:00:54 PM]