There have been many threads recently about using UT with OpenGL. So I thought it would be a good idea to pool as much information as possible into one thread.
When UT first came out in '99 the 3dfx Voodoo cards were the best accelerator to use, they used their own API called Glide. UT would default to using this API if you used a Voodoo card. Now though things are a little different. The two main graphics card producers are ATi and Nvidia, their hardware does not use glide, instead two more API's can be used.
The first is Direct3d or more commonly known as DirectX. While this gives good framerates and image quality, it has it's drawbacks ALT+TAB or minimising UT would cause the PC to hang while the API and your graphics card was working out what was going on. Another drawback was that the CD2 textures of the game would not work correctly, so you ended up installing 350mb of textures that looked no different.
The second is OpenGL which is an open source API. As people upgraded their machines, out went the classic Voodoo cards and in came an ATi / Nvidia card. Alot of the old school UT players who played on Glide dont like the way UT renders in Direct3d. UT did support OpenGL from the very first version, but the renderer was buggy and often caused more problems for the UT player (missing textures etc)
During UT's lifespan a clever chap decided that he'd make his own UT OpenGL renderer. He has steadily increased the feature set and performance of the renderer and most serious UT players will use it. It gives a nice crisp, clean look and delivers in most cases higher framerates.
What do you need to use OpenGL?
Make sure you have the latest video card driver installed, links at bottom of page.
Now you need to download and install the updated UT OpenGL renderer, it can be found here
http://cwdohnal.home.mindspring.com/utglr/
Scroll down to the bottom of the page, and download the version of the renderer that you want. i.e utglr31.zip (this is the latest renderer and the one that I would recommend that you use). There are previous version and the source code available too. Once downloaded you must extract the contents of the zip file to your UT system folder, if you need a program to extract the contents try winzip or winrar. When asked if you want to overwrite the existing file click on yes.
Now that the renderer has been installed, its time to tweak out the Unreal Engine!
Go into your UT system folder and look for this file
unrealtournament.ini
Open this file with notepad or another word processing program. Once the file is open look for this line (use the Edit > Find option in notepad)
[OpenGLDrv.OpenGLRenderDevice]
Delete the 6 lines of code that are there. Now you are ready to insert and enable the new features of the renderer.
Below is my opengl settings for UT just copy and paste into your unrealtournament.ini
[OpenGLDrv.OpenGLRenderDevice]
RefreshRate=85
DetailTextures=True
UseTrilinear=True
UseS3TC=True
UseTNT=False
LODBias=0.000000
UseMultiTexture=True
UsePalette=True
UseAlphaPalette=False
Translucency=True
VolumetricLighting=False
ShinySurfaces=True
Coronas=False
HighDetailActors=True
MaxAnisotropy=0
AlwaysMipmap=True
UsePrecache=False
SupportsLazyTextures=0
GammaOffset=0.000000
MaxLogTextureSize=0
MinLogTextureSize=0
MaxLogVOverU=0
MaxLogUOverV=0
MaxTMUnits=0
NoFiltering=False
DisableSpecialDT=False
UseFilterSGIS=False
Use4444Textures=False
UseVertexSpecular=False
UseTruform=False
ShareLists=False
DescFlags=0
Description=
TruFormMinVertices=0
TruFormTessellation=3
AAFilterHint=0
NumAASamples=0
UseAA=True
RequestHighResolutionZ=True
MaskedTextureHack=False
FrameRateLimit=0
SwapInterval=-1
UseVertexProgram=False
UseCVA=False
UseMultiDrawArrays=False
TexDXT1ToDXT3=False
DynamicTexIdRecycleLevel=100
UseTexPool=True
UseTexIdPool=True
UseSSE=2
BufferClippedActorTris=True
SinglePassDetail=False
ColorizeDetailTextures=False
DetailClipping=False
UseDetailAlpha=True
AutoGenerateMipmaps=False
UseBGRATextures=True
UseZTrick=False
OneXBlending=False
GammaCorrectScreenshots=True
GammaOffsetBlue=0.000000
GammaOffsetGreen=0.000000
GammaOffsetRed=0.000000
Descriptions of what each setting does can be found on the renderer page at the top. Ati Radeon owners may want to set UseTruform to True for an interesting effect. Depends on personal preference really.
A word of warning, the first line specifies the refresh rate to run the game at, make sure you set this to the same refresh rate as your desktop. If you are unsure of your refresh rate put it to 60, all modern monitors are capable of running at this refresh rate.
Save the unrealtournament.ini and fire up UT in safe mode. Click change your 3d device, tick show all devices and select OpenGL support. Click Next, Next and then Run. UT will now boot up in OpenGL.
You may have to adjust the brightness within UT, especially with ATi Radeon cards, ATi broke the gamma control in an earlier catalyst driver and with some cards / driver sets its still a bit iffy. I dont really find it a problem, pressing F11 ingame will increase the brightness for you.
Now some links
The renderer
http://cwdohnal.home.mindspring.com/utglr/
Ati Drivers
http://www.ati.com/
Nvidia Drivers
http://www.nvidia.com/page/home
Winzip
http://www.winzip.com/
Winrar
http://www.rarlab.com/
Much kudos to the guy who continually supports our game with his efforts on the renderer. Thanks man
I take no responsibility if you manage to mess up your unrealtournament.ini file or if your game develops faults / crashes. I have used these settings for almost 4 years know with no problems. So do so at your own risk.
Cheers
vit
UT Open GL Resources
I'm gonna make it a sticky for a while 
Linear Mode
