Banded SW Lightmode - ?

[Sergeek]

This option in GZDoom Hardware Renderer settings puzzled me to no end. All the guides I've read never had any explanation for it. It was switched off by default - when should I enable it?

[dpJudas]

The math for software light is a linear interpolation that darkens the light based on distance to the camera and the light level. If you use the software light mode it will use this equation as it was ideally meant to look if Doom had been rendered in true color. You can additionally turn on radial distance calculations to make it even more visually "correct".

 

However, Doom was not a true color game. Instead of using the ideal value the game used 32 shades via lookup tables. This is why if you launch any of the ports that uses palette rendering you'll see the light darken in distinctive steps (bands). Banded lightmode simulates this behavior for those that doesn't want the ideal look, but rather wants the look of the original software renderer. If you mix the banded lightmode with the palette tonemap you will get very close to how the game looked like if you used the original software renderer.