View Full Version : Doom 3: OpenGL, right?

08-14-04, 06:13 PM
Hey guys.
Doom 3 runs on OpenGL, which is why nVidia cards do so well on it, right? Why does the Doom 3 installer contain DirectX 9.0B in the "extras" section? It boggles the mind - how would having a new version of DirectX affect this game if it uses OpenGL?

08-14-04, 06:33 PM

08-14-04, 06:38 PM
It thought it was funny also... when installing the game it said "You need to have dx9b installed or it will not function."

08-14-04, 06:47 PM
Yeah, what's up with that? Can someone enlighten me?

08-14-04, 06:51 PM
Direct X 9b doesn't just involve the graphics...it effects many parts of your system ... direct x deals with keyboards, joysticks, sound mixing, etc...it basically helps make everything multimedia wise work together well

and i believe openGL also can utilize some direct x effects...not sure on that one...i think openGL has shader model 2.x capabilities

here's a quickie definition from http://webopedia.internet.com/TERM/D/DirectX.html

A set of APIs developed by Microsoft that enables programmers to write programs that access hardware features of a computer without knowing exactly what hardware will be installed on the machine where the program eventually runs. DirectX achieves this by creating an intermediate layer that translates generic hardware commands into specific commands for particular pieces of hardware. In particular, DirectX lets multimedia applications take advantage of hardware acceleration features supported by graphics accelerators.

maybe when ID was developing the game they were using dx 9.0b in their hardware so the end useres would need it as well...

08-14-04, 08:01 PM
DirectX is the entire API that allows all your hardware to interact with a game. Direct3D is the graphical component. As has been mentioned, you also have Direct Sound, Direct Play and other components.

Saying that a game is DirectX (as compared to OpenGL) is a bit of a misnomer.

08-14-04, 10:11 PM
Ah, I see. That makes a little more sense. Thanks for the quick and informative reply!