Rage, opengl and megatextures

[MarcVenice]

So, instead of doing my own research I'm going to ask you guys, and hopefully a nice discussion can come out of this. The new engine is going to use opengl, instead of directx, because those two are basicaly competitors, right?

If I'm right, then what does this opengl thing mean, how is it different from directx, and since all videocards tout their directx capabilities for marketing reasons, what does this mean for a opengl game? How do directx10 videocards perform when a game runs on opengl? Whats the difference between ATI and Nvidia? Image qaulity ?

Last but not least, there's a pretty difficult explanation from John Carmack about those megatextures they will be using, but I couldn't make anything out of it, went completely over my heard, anyone care to explain ?

 

[tuteja1986]

The engine will run on both : OpenGL and DirectX 9. Its an sort big advancement in multi-platform as when they click build :! it builds automatically playable build for the PC , PS3 and 360. Its also a server based engine.

 

[The Keeper]

http://en.wikipedia.org/wiki/Opengl

OpenGL does not equal DirectX. OpenGL is only a graphics API while DirectX consists of graphics, audio and input APIs at least. OpenAL does audio. There is also another Open API for inputs but I've forgotten its name, but I don't think it has received any popularity yet.

There is no significant difference between Direct3D and OpenGL API performance. What difference there is usually depends how well a game has been optimized for the particular API. Of course performance comparisons are difficult unless a game has both Direct3D and OpenGL engines, which is rare and usually either one lacks proper optimization on PC platform at least. There is not much to say about differences between ATI and NVIDIA, just take a page from Direct3D differences for what its worth.

 

[frythecpuofbender]

What I find pretty intriguing is the possibility of having the textures streaming only when they are visible on the screen.
I don't understand how the engine knows what will be seen next, but it could be a similar breakthrough like engines being able to hide polygons that aren't drawn on the screen.
No more loading 512MB textures right up front and the leveldesigner only being able to use that space and not more.
Levels could have way more detailed artwork, less repetitive.
Only problem I see is
1. XBOX DVDs will get scratched even more MUAHHAA stupid decision not to include a harddrive from the start
2. artists are able/need to create even more content for next-next-gen titles.

 

[BassBomb]

Pretty sure its DX only now. Check the pc gaming forum

 

[darckhart]

I remember hearing somewhere that the opengl aspect was only for mac support as carmack decided to stick with dx9 for pc/360. might have been in that gametrailer video actually.

 

[BFG10K]

Originally posted by: BassBomb

Pretty sure its DX only now. Check the pc gaming forum

That claim was debunked.