ZDoom

GZDoom 1.6 was very different than later versions, it was a hybrid engine combining fixed function rendering and shaders. It was capable of enabling some effects in a very limited fashion on older hardware but the entire setup was not maintainable, and even the minor use of shaders it had impacted this hardware too much.

The moment the modern render path transitioned fully to shaders the game was over for older hardware.

I remember that gzdoom 1.6 had functional brightmaps and in OpenGL 2.x

Brightmaps and those shader based lighting modes were never implemented for OpenGL 2.x, from the beginning they were GL 3.x.
The shader hardware on GL 2 hardware is far too slow to run such complex stuff.

Your graphics adapter is the problem (apparently you are playing with LEGACY GZDoom because Modern simply doesn't start as it requires GL3 or GL4), in new GZDoom versions brightmaps only work if your graphics card supports at least OpenGL 3, the same applies to some sector lighting modes like software, doom and vanilla and postprocessing that is not available. I'm not sure why Graf decided to remove these effects for OpenGL 2 mode, but software sector lighting mode was working absolutely fine in GZDoom v2 with OpenGL2 mode. Also not sure if Zandronum (which is based on very old GZDoom open gl2 port) supports brightmaps, if I remember correctly it does.

LZDoom which is stripped down version of new GZDoom for old graphics cards like yours doesn't include support for these sector lighting modes and brightmaps that old OpenGL2 based GZDoom v2 had. Gotta remind this to drfrag :mrgreen:

Intel Hd Graphics. i don't think the graphics card is the problem because it is working in GZDoom 2.2, but if it is: fuck.

First, there has never been a 3.9 version. Second, what kind of graphics card do you have?
BTW, ports like Crispy Doom and ZDoom do not have brightmaps, so they cannot work there. All they can do is use colormaps with special fullbright colors.

I've been Modding [b]GZDoom [/b]for a little while, and i notice that in versions like 3.5 to 3.9 the [b]brightmaps [/b]just don't work.
You could say that is my Graphics card that is the problem, but i Doubt, in the 2.2 version of [b]GZDoom [/b]they still wok just fine, even in other source ports like [b]Crispy Doom[/b] and [b]ZDoom[/b] they still working just fine.