Brightness and contrast D3D vs OpenGL

[j7n]

Yesterday I downloaded and installed this updated OpenGL renderer in Unreal v226: OpenGlDrv2.1.0.6_Gold.zip. Installation was as easy as dropping in the DLL and tweaking a few settings to raise the quality. It works much better than the Direct3D one, which was incompatible with anti-aliasing (half-pixel wide border around the picture).

But I noticed that the game has much more light now. Most scenes give dynamic, saturated, full range picture like it's Christmas. I quite like it. I previously beat the game while it was dark, and found it quite challenging on an LCD screen, which I assumed was intentional. *Why* is it that the standard "official" renderer outputs such a dark picture?

( screenshots omitted because of spam protection )

It is not a matter of the overall gamma, because the brightness of the large box to the right and the pistol doesn't change. Rather objects radiating light such as lamps, the sky or TV screens are great deal brighter. My "brightness" setting is 0.4, video adapter is GT 610.

[Smirftsch]

well, if you really want to do a comparison you should compare with a glide capable card or at least a glidewrapper. D3D was never "perfect" either and on nowadays systems it's often not working correctly anymore anyways.
D3D9 and OpenGL however offer a wider spread of gamma correction options including gamma correction for screenshots.
Another difference is "OneXBlending" - while Unreal looked in the first place much more colorful (f.e. in v200) people got used later to the "washed out look" in D3D (v224-226)- so D3D itself already was a change. You can toggle this in the advanced options with the OneXBlending option.
Check f.e. here: http://www.oldunreal.com/cgi-bin/yabb2/YaBB.pl?num=1340587646/4#4

or use the advanced search in the forums with the keyword OneXBlending, you'll find a couple of topics related to that

[j7n]

I have never played the game on a Voodoo Glide. Instead I started with a Pentium II in software mode. A rock solid Windows 2000 system, without 3D hardware. A Voodoo probably costs a premium these days.

I thought that OpenGL was presented this way by nVidia, because my Half-Life also has very high constrast. But now I can see it can do both ways. The setting is not part of OpenGlDrv2.1.0.6_Gold.zip, which I am content with, but toggling it in Unreal Tournament (utglr36.zip) does indeed return the previous contrast level. I'm a bit lost among all the mods out there for classic games, and I've added the least amount of updates only (namely the two opengldrv.dll files).

With OneXBlending to False, a gamma correction doesn't seem to be needed for me. Slightly raised gamma never looked right before. Some objects and the Gold menu looked washed out.

The scene from that thread looks better with False to me. The body and the barrel receive about the same light as the wall. Whereas under Direct3D, the objects look superimposed onto the darker wall. (quite different from Shoober420's result) Same with the large box, which is glowing for no reason under Direct3D.

D3D:


OpenGL:


Software:


The settings I use. + 8x antialiasing in nVidia control panel.

[OpenGLDrv.OpenGLRenderDevice]
Translucency=True
VolumetricLighting=True
ShinySurfaces=True
Coronas=True
HighDetailActors=True
DetailTextures=True
GammaOffset=0.000000
LODBias=0.000000
MaxLogTextureSize=8
MinLogTextureSize=1
MaxLogVOverU=8
MaxLogUOverV=8
MaxAnisotropy=8
MaxTMUnits=3
RefreshRate=75
DetailMax=3
UseFisheye=False
NoFiltering=False
DisableSpecialDT=False
; distant textures were aliased and didn't
; seem to use trilinear with SGIS
UseFilterSGIS=False
Use4444Textures=False
UseTNT=False
UseS3TC=False
UseVertexSpecular=True
AlwaysMipmap=False
UseAlphaPalette=True
UsePalette=True
UseTrilinear=True
UseMultitexture=True
ShareLists=False
DoPrecache=True

The [url=http://www.vogons.org/viewtopic.php?f=5&t=42000]bug[/url] with DirectX anti-aliasing was the deal breaker for me, why I went for OpenGL. Use DirectX 10 and Vista for a game from 1999? I don't think so. : )

[Smirftsch]

as said, you could still use a glidewrapper to compare, I think these come very close.
As for OpenGL, you can try the beta 0.99 version for 226 which can be found here:
http://www.oldunreal.com/specialpatches.html

it should contain this setting, or you could give 227 a try which includes a later version as well (but I assume you want to stay with 226).

[j7n]

The multimedia patch 0.99 also works. It defaults in dark mode and, by setting OneXBlending to false, switches to bright mode. Also apparently the official OpenGLDrv.dll does work on ancient video adapters (instead of crashing). It is also dark.





The Flightcastle looks incredibly awesome with the hellish red glow inside and the reflective walkway!! Good job, Chris Dohnal. I'm sold that these are the right colors, and will probably play through another time to see everything. Also, the DLL does still load on Win98 (atm I can't whether it operates correctly due to lack of a 'powerful' w98 system).

OneXBlending FALSE:


OneXBlending TRUE:


The light level aproximately matches the Voodoo screenshot on [url=http://en.wikipedia.org/wiki/Unreal#Graphics]Wikipedia[/url], although they hack, slash and subsample all non-free pictures to please the 'fair' copyright police that you never know.

[han]

One thing which came to mind in the last days was, that always these how Unreal should have looked liked are based around OneXBlending, Multi vs. Singletexturing, etc. but it seems that one major aspect is always missing: The monitors color profile (Thats more then just a gamma ramp!). I guess thats also an important factor why it looks with Render X and setting X less colorfull, or you can't see shit, etc. And a bad color profile actually reduces the overal visibility and quality very much.

[Hellkeeper]

Good job, Chris Dohnal. I'm sold that these are the right colors, and will probably play through another time to see everything.

I'll chime in just to say I've always been amazed at how bright people seem to have their game set. It might be because many people have the game "balance" gamma on taking screenshots, making screens ultra-bright, but most UT/Unreal screens are very whitewashed and luminous while both games seem like they should be quite dark. I'd say the best (what seems "correct" to me) brightness setting is one step down from default on the UMenu slider. I believe that's why, when I released Piraeus, people were able to see the end of the sea and the junction with the skybox, while my darker settings meant you couldn't and some parts of the map were in almost pitch-black darkness.

[han]

This article might be interessting as it covers gamma correction on textures too.
http://gamedevelopment.tutsplus.com/articles/gamma-correction-and-why-it-matters--gamedev-14466

/edit:
SGLDrv seems to be actually gamma corrects the textures too, and i get the same blue tint when loading stuff as SRGB, while GlideDrv doesn't seem as it have handled them ever as sRGB (or this handling was implicit in Glide API).

And gammacorrecting textures was quite an expensive task for the SGLDrv, so it must have been put in for good reasons.

/another edit:
Okay this gets even more weired. I now ended up giving the the supposed to be RGBA7 lightmaps a try as loading them as RGBA8, and actually against my expectations the game didn't end up totally dark, but it yielded a slightly better visual quality and especially better visibility.

[j7n]

I've always been amazed at how bright people seem to have their game set. It might be because many people have the game "balance" gamma on taking screenshots, making screens ultra-bright, but most UT/Unreal screens are very whitewashed and luminous while both games seem like they should be quite dark.

I have seen pictures of the Flightcastle posted with gamma increased significantly, as a demonstration of Unreal's graphics. The castle should of course be low-key, but with good contrast throughout. After finishing the game with openGL, I get then impression that all objects now belong in the environments they are in, whereas with OneXBlending they often look superimposed over walls. A gamma in the monitor or video adapter of course affects the color of everything equally, walls and objects.

"The Darkening" level was also very much playable. I get about 4 levels of blue on walls and the weapon without using the searchLight or shooting, but only half that with D3D.

With openGL the game also starts and exits "cleanly". No longer I see the Windows desktop increase in brightness momentarily (because I don't use a gamma correction anymore), and the game doesn't hog the CPU after I quit it (or alt-tab).

[medor]

if you want try the glide ( the native unreal render ) with Voodoo files.
http://unrealtournament.99.free.fr/utfiles/index.php?dir=Video_Renders/Glide/&file=dgVoodoo1.50Beta.zip
You have to put the 2 .dll and the .vxd and the .ovl in \System.

For make it work in 32bit http://www.zeus-software.com/downloads/nglide