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id Tech 3 => Engine => Topic started by: fromhell on June 20, 2016, 07:31:21 PM



Title: How does the fog work?
Post by: fromhell on June 20, 2016, 07:31:21 PM
From what I get Q3's fog system seems to be a projected texture on all the polygons it covers and it isn't really real fog. It seems heavily emulated, and forces modulation of a fog color on anything it hits (including flares)

is this right? Because I am having a hard time understanding the fog operations in q3, it's not standard opengl fog functions


(wanted to make some way to have smooth edged spherical fog ala UE1 as well as Doom3-ish volumetric flares)


Title: Re: How does the fog work?
Post by: Gig on June 21, 2016, 12:37:28 AM
Googling a little, I found this thread:
https://www.opengl.org/discussion_boards/showthread.php/146347-How-to-render-Quake-3-volumetric-fog
Yes, it looks like id software did not use OpenGL fog functions, but used some trick instead.

Other pages mentioning Q3 fog do not seem to be very useful...
http://www.gamedev.net/topic/287308-quake-3-volumetric-fog/
http://www.game-artist.net/forums/showthread.php?t=79