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B_O_T
02-17-2002, 08:24 AM
Hi guys!

Does anyone know how do such a fog as seen in new Wolfenstein?
It doesnt look like Q3 fog and its a lot faster.

Nutty
02-17-2002, 10:54 AM
You mean the radial fog?

IF you look dead on at something that is foged in Wolfy, and then turn, so it hits the edge of the screen, it becomes unfogged. It's not as accurate as linear fog.

There is a radial fog example in the Nvidia Effects Browser.

Nutty

B_O_T
02-17-2002, 11:46 AM
So, its just a vertex fog, am I right?

dorbie
02-17-2002, 12:13 PM
Do you mean the layered fog effect?

B_O_T
02-17-2002, 12:53 PM
I mean volumetric fog on the floor.

knackered
02-17-2002, 01:30 PM
A quick way (in vanilla opengl) would be to use 2 user clip planes, render the scene twice, once with the clip planes and fog enabled, the second time with the clip planes normals inverted and fog disabled.
Another way would be clever use of the fog coordinate extension.
Q3 (and wolfenstein) don't use proper volumetric fog - just a estimate.

Michalek366
02-18-2002, 01:29 AM
On my TNT2 card fog coord doesnt work!

What to do? :->

[This message has been edited by Michalek366 (edited 02-18-2002).]

dorbie
02-18-2002, 06:26 AM
That's layered fog. It is a layer of fog which behaves volumetrically.

It was also there in Quake3.

You can do this with texgen with the right radially mapped texture, but AFAIK the trinity engine cuts the model to generate extra vertices and uses per vertex fog color.