DRD Team

Hi there,

I'm mainly using GZDoom to play the 'ol doom games with sexier graphics but I noticed somthing's slighty amiss. The player in the Doom games seems to emit his own light that brightens walls / creatures in dark rooms as you get closer to them - but this doesn't happen with GZDoom (though swtiching the render to software or just using ZDoom does... but looks crap:)

Is it something I'm doing wrong or have missed?

I've tested this on my desktop & laptop - both use Radeon cards (desktop gfx card is a Radeon X800.) I'm using the latest versions of ZDoom & GZDoom on WinXP.

Thanks

The effect you are talking about is the software renderer's "Doom fog" as most people call it.

The Doom fog is not easily achievable using the OpenGL renderer. Graf Zahl may have more technical information but all I can tell you right now that if it could have been done easily, it would have been done a long time ago.

The lack of the Doom fog also leads to some bland-looking lighting in maps when using OpenGL. It's not a big issue really but yes it does make it not look like the Doom you are used to seeing.

Currently the only port I'm aware of that emulates Doom fog in OpenGL correctly is EDGE.

I'm sure Graf would like to implement it eventually though.

There IS some fog in GZ's opengl, it's just faint and not very customizable. There's about 5 settings for it and none of them use as severe fog as software renderer. Putting sector light level on "standard" is closest, though.

Unfortunately the hardware based fog is not customizable enough. And using shaders for this causes too many problems with the renderer. It just was never designed for shaders.

Graf, how does EDGE pull it off? Is it using some hardware features that older graphics cards can't do?

No. It splits polygons across fog density boundaries.

Thanks for the replies & info guys. Using the sector light level at standard does brighten up some of the darker parts so that'll do.

Graf Zahl wrote:No. It splits polygons across fog density boundaries.

Is this something that can be done with your renderer?

It's something that can be really, really messy. I'd rather not bother with it and its implications.