Direct X and OpenGL differences.

[Kazuki_Fuse]

I know it's probably hard to explain, but I was wondering what the different rendering capabilities that DX9 and OpenGL 1.5 have? Like for example, is HDR a Direct X only effect? I was just curious because of all the Doom3 vs HL2 posts popping up, and was wanting to know what advantages and disadvantages the two renderer's have over one another. I know that DX is used far more, but why? Anyone know?

 

[umop]

That's a good question, I wonder that every once in a while. The only thing I can say about it from experience is that the mouse movement properties seem a lot different. In almost all DX games, there tends to be a slightly noticable mouse lag when the computer is heavily stressed, where in Open GL it doesn't seem to be very often. Maybe I'm just crazy but I'm a sucker for OGL because of that.

 

[Para]

It's quite simple actually.

1) OpenGL is just graphics API, DirectX contains 3D, sound and music, input devices (keyboard, mouse, joystick), networking stuff and media handling API:s. You can also ask directly from Microsoft for help if your DX application isn't working the way it should be + it has a lot of documentation over at MSDN.
2) D3D had shaders before OpenGL. Yep, there is vertex, pixel and fragment shaders in OpenGL, but those are not as widely supported and not as fast nor complex as D3D counterparts and to top it, you have to do some registry tweaking to get them to work on nVidia cards. D3D shaders come "out of the box" without any kind of tweaking needed.

All the nifty effects are possible to do in both OpenGL and D3D, but D3D wins in speed and most often also in time neeeded to achieve the effects.

 

[Kazuki_Fuse]

See I always thought that OpenGL was a faster API. And that it supported cross platform much better than OpenGL? I had no idea about that stuff, thanks man.

 

[Para]

There isn't a good way to test both APIs to find out which one is faster, OGL or D3D since in both you can do the same thing (like Lambert-shading a sphere) so many different ways which will all perform differently on different cards that the comparison is near impossible. The shader stuff is true though since there is no true GLSL support at the moment (or so I've been told), all GLSL stuff is emulated thru HLSL or something...not my area of expertise actually

OpenGL is of course very portable between different platforms - even certain mobile phones and PDA:s have OpenGL ES support. In reality there's just no point in doing a fully portable product since 90% of people use Windows, 5% MaxOS 9&X, 3% misc. OS:s and 2% Linux. Since DX is Windows-only and has a lot of support behind it, it's usually very easy to say why devs should do their stuff with DX (I'm talking about the whole API now) to achieve 90% coverage of all users instead of using OpenGL + who knows what kind of tweaks to get everything else working to get the last 10% covered. It's just not financially approvable thus not worth the effort.

 

[EVIL]

This isn't the right forum for this question either, it should belong either in the "Hardware, Software & Troubleshooting" forum or the "General Gaming" forum, let the mods decide!

 

[Kazuki_Fuse]

Oh Shit! What's the world coming to?? My bad, I couldn't resist. The post does mention HL2 and could be integrated into the thread. I dunno I'm probably wrong, I should've posted somewhere perhaps more appropriate.

 

[Crusader]

This isn't the right forum for this question either, it should belong either in the "Hardware, Software & Troubleshooting" forum or the "General Gaming" forum, let the mods decide!

Oh, damn. The most interesting topic we've had here in a while and it's going to get moved...

 

[Lanthanide]

I too often find that is the case. I read an interesting thread here, and then next time I log on the mods have moved it to another forum. Kind of annoying actually.

 

[ewilson248]

No, This is a relavent topic for this area, I posted the same question a little while back with a different spin, put it in terms of hardware:
Why does the current gaming scene look like this: H2/ATI/DX9 vs D3/NVIDIA/OGL
This still really bothers me, as I feel that if I spend $400+ on ANY new video card and have a decent system to put it in, I should be able to play ANY game AND get high end performance. I am still waiting for someone to give me a legitimate reason why we should have to choose at all.

 

[FictiousWill]

You don't. The differences are like 3 fps.


btw: my forum friend: the New Posts button.